Britain is ready to offer further support to a European operation aimed at controlling borders in the Mediterranean Sea where desperate migrants attempt to reach the continent by boat, Immigration Minister James Brokenshire has said.
The Government has faced criticism for its refusal to support further search and rescue efforts in the sea after the wind-up of an Italian operation that has saved tens of thousands of people making the treacherous journey from North Africa.
It will be replaced by an EU operation more focused on border control to which the UK has so far provided only one debriefing expert, but Mr Brokenshire said the Government stands ready to offer further support.
Labour backbencher Mark Lazarowicz said Britain will be complicit in any migrant deaths if it fails to help the migrants.
Mr Brokenshire said Britain was ready to give further help to EU border management agency Frontex's new Operation Triton in the Mediterranean, which will replace the Italian Mare Nostrum search and rescue mission.
Answering an urgent question in the Commons from Mr Lazarowicz, he said: "We have agreed to a request from Frontex, the EU's border management agency, to deploy a debriefing expert in support of the new Frontex Operation Triton off the southern Italian coast.
"This operation is not designed to replace Mare Nostrum but will instead patrol close to EU borders.
"We stand ready to consider any further request for UK support for the new Frontex operation."
The Immigration Minister also said it would be inconceivable for the EU operation not to come to the aid of a boat in danger.
The new mission, beginning on Saturday, has different aims from the search and rescue-focused Mare Nostrum and will deal primarily with border control and cover a smaller area, according to EU officials.
Mr Brokenshire said: "Those (search and rescue) matters are matters for member states individually in respect of their territorial waters and therefore it is ultimately a decision for Italy as to how it conducts its search and rescue matters.
"In respect of the Frontex operation that I have outlined, that is providing surveillance capability and other support in respect of the border.
"But I find it inconceivable to suggest, and indeed the head of Frontex has said this, that if a boat were in peril that support would not be provided in those circumstances and that obviously rescue would be undertaken."
Mr Lazarowicz said it was Britain's moral duty to act to save migrants in peril in the Mediterranean.
He said: "This policy is shameful.
"Surely when we know that hundreds of our fellow human beings face terrible death, and it is in our power to do something about it, it is our moral duty to act and if we fail to do so, are we not complicit in their deaths?"
Mr Lazarowicz attacked the Government for ignoring refugee agencies' calls to set up more safe and legal channels for people to access protection and for not attempting to set up an EU-wide search and rescue operation.
The MP for Edinburgh North and Leith said the refugees and migrants trying to cross the sea are so desperate they will continue to make the journey whether search and rescue operations are discontinued or not.
He said the ending of search and rescue is cruel, inhumane and illogical.
Mr Lazarowicz said: "You know that many of those seeking to make this journey are fleeing war, poverty and starvation from places like Syria and Libya.
"They know already about the risks of dying... they are exploited by people-traffickers, as you have accepted. If they are picked up by European neighbours or border control, they know that they are not going to be given free entry to Europe but are quite likely to end up in a detention centre in Italy or be sent back to their country of origin.
"Surely it is obvious that the refugees and migrants making these journeys are so desperate they will still make these terrible journeys anyway and the idea that search and rescue operations should be discontinued and people left to die in their thousands to discourage others from making the journey is not just cruel and inhumane, but totally without logic."
Mr Brokenshire said the Mare Nostrum search and rescue mission had the unintended consequence of placing more lives at risk by encouraging people-traffickers to place migrants and refugees in more unseaworthy boats.
He said: "Since Italy launched its Mare Nostrum operation in October 2013, there has been an unprecedented increase in illegal immigration across the Mediterranean and a four-fold increase in the deaths of those making that perilous journey.
"The operation has been drawn closer and closer to the Libyan shore, as traffickers have taken advantage of the situation by placing more vulnerable people in unseaworthy boats on the basis that they will be rescued and taken to Italy.
"But many are not rescued, which is why we believe that the operation is having the unintended consequence of placing more lives at risk."
The Government was criticised by MPs from across the House who branded its refusal to support future search and rescue missions as "deeply unethical" and "repugnant".
Shadow home affairs minister Diana Johnson said leaving people to die "in their thousands" was not the answer and condemned the decision as a "barbaric abandonment of British values".
She also accused the Government of using the situation to divert attention from its failed immigration policy and said it was willing to do anything to appear tough on immigration ahead of the Rochester and Strood by-election next month.
But Mr Brokenshire hit back, saying she was politicising the issue and reminded the House that all 28 EU member states had reached a unanimous decision on this.
Liberal Democrat Sarah Teather (Brent Central) called the move "absurd and deeply unethical", adding: "We can't wash our hands of these people, Pontius Pilate-style."
Keith Vaz, chairman of the home affairs select committee, insisted the solution lay with north Africa and urged the Government to work with those countries to support them in preventing people from leaving in the first place.
Labour's Diane Abbott ( Hackney North and Stoke Newington) said the decision represented a "new low".
She said: "Of course the solution to these problems lies in north Africa ... but consciously pursuing a policy that will allow more people to drown should play no part in protecting Europe's borders.
"We will look back in shame to this decision."
Scottish Nationalist Pete Wishart (Perth and North Perthshire) said he did not think he had ever heard a more shameful statement from the front bench and indicated Mr Brokenshire should be ashamed of himself.
And Labour's David Winnick (Walsall North) said the policy could be summed up in three words - "let them drown".
Conservative Jeremy Lefroy (Stafford) asked why EU member states were not investing in a solution first before removing the safety net.
Labour's Sheila Gilmore (Edinburgh East) asked whether the Government had proof of the "causal link" between the Mare Nostrum operation and the subsequent increase in deaths.
And her colleague Frank Roy (Motherwell and Wishaw) asked Mr Brokenshire to estimate how many lives would be saved by ceasing support.
The minister did not give a number, but said: "The reality is more lives are being lost and have been lost during the course of this year to date than were lost in 2013."
Labour's Barry Sheerman (Huddersfield) said: "Morally, I can't stand by and not say it's repugnant that we leave children and families to perish in this way."
Some backbenchers spoke out in support of the Government, including eurosceptic Conservative Philip Davies (Shipley) who said more and more people had "tried their luck" since the search and rescue missions began, "w ith the result we have had more and more illegal immigrants and more and more deaths".
"The message that should go out from this House is ... to tell people to stop trying their luck in the first place."
Veteran Tory and former minister Sir Tony Baldry accused those who had spoken out against the decision of being "out of step" with all the home affairs and justice ministers of the EU.
Responding to the debate, Maurice Wren, chief executive of the Refugee Council, called the Government's contention that search and rescue operations encourage people to take perilous journeys "an affront to basic humanity".
He added: "The suggestion that if we allow people to drown at sea it will deter others from fleeing persecution is macabre logic.
"Future generations will surely look back with shame at the British Government's response to the greatest refugee crisis in generations, a s it stands on our island, pulls up the drawbridge and callously leaves desperate people to drown while telling them it's in their best interests."