Big guns in pre-campaign skirmishes
With 100 days to the general election, the parties have wheeled out their big guns for a campaign which appears to be shaping up as "wealth versus health".
David Cameron promised he would act "within the first few days" of forming a new government to cut the annual benefits cap introduced by the coalition from £26,000 to £23,000 per household, using the £135 million savings generated to help fund three million apprenticeships by 2020.
Meanwhile, Labour launched a 10-year plan for the health service, with a warning from leader Ed Miliband that "the future of the NHS is at stake" in the May 7 poll.
And Liberal Democrats released an online advert to back their appeals for inclusion in a new coalition to temper the excesses of the two larger parties, warning that a Labour-only administration would deliver "reckless borrowing" and Tories governing alone "reckless cuts".
Mr Miliband accused Mr Cameron of "wriggling and wriggling" to get out of taking part in the proposed round of televised live leaders' debates during the election campaign, after the Prime Minister suggested he would not take part unless the broadcasters included Northern Ireland in the line-up.
Mr Cameron insisted he wanted to say "Yes" and believed a deal could be done, but blamed the broadcasters for putting forward a format - including Ukip, the Greens, the Scottish National Party and Plaid Cymru, but not the Democratic Unionists - which "doesn't quite make sense".
Speaking to LBC radio, Mr Cameron insisted he was "not fighting shy" of the debates, but joked that viewers might anyway prefer to be watching the BBC's latest historical drama, saying: " If people want to watch a television debate or if they prefer an episode of Wolf Hall, that's up to them."
An opinion poll released with 100 days to go suggested the two main parties remain neck-and-neck in the race to 10 Downing Street, with a hung Parliament the most likely outcome.
The Survation poll for the Daily Mirror had the Tories on 31%, a fraction ahead of Labour on 30%, with Ukip surging to a high of 23%, Lib Dems on 7%, the SNP on 5% and Greens on 3%.
Mr Cameron acknowledged that the election would be close, but warned that the country faced a stark choice, with the election of a Labour government led by Ed Miliband and Ed Balls risking a return to economic "chaos".
"It is going to be, obviously, a very close and tough fight but I think we have a really strong offer for our country," he told Sky News.
Noting the election of a left-wing administration in Greece, the PM added: "Obviously I am worried about the future of our country if we end up with an unstable, left wing government that starts to borrow and spend and wreck the progress that we have made. Of course I worry about that."
Mr Cameron rejected claims that the lower benefits cap would plunge more families into poverty, saying members of the public had repeatedly complained that it had been set too high. He said there had been "a change of culture", with voters now believing it was "unacceptable to opt for welfare as a lifestyle choice".
"This is a basic issue of fairness. I don't think a family should be able to get more in benefits than someone going out to work, working every day, and trying to do the right thing for them and their family," he told the BBC Radio 4 Today programme.
He confirmed that regulations to tighten the limit - which are expected to mean an additional 40,000 households seeing a reduction in state help - would be among the first priorities of a Conservative administration.
The maximum loss - on top of the effects of the existing cap - would be £60 a week, with an average weekly loss of around £40 or £25 for those newly capped.
Another £120 million would come from removing housing benefit from 18 to 21-year-olds on Jobseeker's Allowance.
Speaking in Trafford, Manchester, where the first NHS hospital was opened in 1948, Mr Miliband warned: "One of our country's most precious institution faces its most perilous moment in a generation. The future of our NHS is at stake in this general election."
The Government had allowed a crisis to build up in NHS A&E departments by neglecting the action on social care, mental health and GP services which can keep people out of hospital, he said. And he warned that victory for the Conservatives in May would usher in changes which would leave the NHS "unrecognisable".
Labour's 10-year plan, launched by shadow health secretary Andy Burnham in London, focuses on previously-announced promises to invest an additional £2.5 billion in the NHS, recruiting 20,000 more nurses and 8,000 GPs, joining up health and social care and guaranteeing GP appointments within 48 hours and cancer tests within a week.
But it also offered new home safety checks for people at risk of hospitalisation, to provide facilities like grip rails to prevent falls and advice on heating to avoid coldness-linked illness
Mr Burnham promised an army of 5,000 new "homecare workers" to help people leaving hospital and enable the terminally-ill to die at home, as well as changes to social care budgets to end the culture of 15-minute visits to frail and isolated older people.
He warned that "false economies" in social care have helped drive up the number of avoidable hospital admissions to a record 500,000 last year, at a cost to the health service of around £1 billion, w ith one in 10 over-75s and one in five over-90s experiencing avoidable hospital admissions last year.
Launching the Lib Dem advert - which cheekily mimics a previous Conservative poster - Deputy Prime Minister Nick Clegg said: "The Conservatives want to veer off from the sensible economic plan we have set in coalition, towards much harsher cuts than necessary to public services, especially in education. And Labour want to take us in the direction of reckless borrowing, threatening the economic recovery.
"Britain needs a liberal voice in Government, keeping the country on track, and stopping Labour and the Conservatives from lurching to the extremes of left and right."
A poll by ComRes for ITV News found that 55% of voters would prefer Mr Cameron to continue as prime minister after the election, with 45% opting for Mr Miliband.
The NHS (50%) and immigration (49%) were the issues most important to the public, with Labour (32%) the party most trusted on health and Ukip (33%) on controlling immigration.
Katharine Peacock, managing director of ComRes, said: "With a hundred days to go, the general election is absolutely wide open. David Cameron's strong personal ratings are helping his party stay in the race while Labour's once-comfortable lead has disappeared.
"Voters are now seriously considering their options and we're beginning to see the defining electoral issues come to the fore."
:: ComRes interviewed 2,039 British adults online between January 23 and 25.