David Cameron has been accused of putting the interests of the Conservative Party ahead of the British people after he confirmed that Government ministers can campaign on either side of the in/out EU referendum.
Jeremy Corbyn said the Prime Minister's insistence that the Government will have a "clear position" on Britain's EU membership despite ministers being allowed to campaign to leave or remain will make the country a laughing stock.
He spoke after Mr Cameron confirmed that normal rules would be suspended and ministers could campaign for either side once the renegotiation of Britain's EU membership was complete.
Replying to Mr Cameron's Commons statement on the EU, Mr Corbyn said the PM's renegotiation had failed to deliver significant reform because he did not have enough allies in Europe.
The Opposition leader told the Commons: "Can you really be surprised at your failure when you haven't worked with negotiating partners in Europe, failed even to turn up when asked for help in the European refugee crisis?
"To deliver change you need patient, effective diplomacy and you need to make friends.
"We all value our friends, but you are not interested in that - you are more interested in your own party.
"You are really playing politics rather than putting forward the interests of the people of this country.
"Can you now explain whether your Government will have a view on the choice facing the people of this country in the referendum and how it will be reached and expressed?
"What do you have to say to Lord Heseltine, who said Britain would become a laughing stock across the world if you made the announcement you have today?
"Leaders across Europe can see that your demands are actually a bluff, a fig leaf for Conservative Party politics.
"Do you accept that your bluff has now been called?"
Mr Cameron had earlier set out his plans for how the Government will conduct itself in the lead-up to the referendum, which will be held before the end of 2017.
The Prime Minister's decision to allow openly Eurosceptic ministers to campaign to leave or remain in the EU marks a significant shift from the usual assumption of collective Government responsibility.
In his statement on last month's European Council, Mr Cameron said: "My intention is that at the conclusion of the renegotiation, the Government should reach a clear recommendation and then the referendum will be held.
"But it is in the nature of a referendum that it is the people, not the politicians, who decide.
"As I indicated before Christmas, there will be a clear Government position, but it will be open to individual ministers to take a different personal position while remaining part of the Government.
"Ultimately, it will be for the British people to decide this country's future by voting In or Out of a reformed European Union in the referendum that only we promised, and that only a Conservative-majority Government was able to deliver."