Figures suggest almost 600 fewer GP surgeries in England open at evenings and weekends than before 2010, Labour has claimed.
Health spokesman Andy Burnham said the coalition had created queues outside practices and diverted people to AE.
Tory Health Secretary Jeremy Hunt said Labour’s numbers were wrong and that out-of-hours cover was being extended.
The Lib Dems also said Labour’s figures – obtained through a parliamentary question – were out of date.
Mr Burnham announced the analysis as his party unveiled a new poster, which reworks the Conservatives’ “Labour isn’t working” image of 1979 by depicting a huge queue outside a waiting room with the title: “The doctor can’t see you now.”
“On all the indicators it is clear that GP services have gone backwards in this Parliament,” he told the BBC.
In other election developments:
- Nick Clegg will set out how the Lib Dems would use the proceeds from a crackdown on tax evasion to fund income tax cuts
- David Cameron will campaign in Scotland, Wales, Northern Ireland and England in a single day
- Tony Blair will enter the campaign for Labour with an attack on the Conservatives’ Europe policy
- Research for BBC Scotland suggests voters in Scotland favour targeted public spending ahead of efforts to eliminate the deficit or cut taxes
- Nigel Farage dismisses calls from Mr Cameron for UKIP supporters to “come home” to the Conservatives
Policy guide: Health and care
This issue includes NHS funding, GP access and social care, particularly of older people.
Labour has pledged £2.5bn to pay for 8,000 more GPs, guaranteeing appointments within 48 hours.
Mr Burnham said the last Labour government had introduced an extended-hours scheme which, in 2009, funded 77% of surgeries to open on evenings and weekends.
The Commons answer suggested the coalition had reduced extended access funding in England from £3.01 per patient to £1.90 per patient, meaning that – by 2013/14 – 72% of surgeries offered extended hours under the scheme, a reduction of 590, according to Labour’s interpretation.
Mr Burnham told BBC Radio 4’s Today programme that many people were not able to book appointments for days and, as a result, ended up at AE. “If you are going to have a truly preventative NHS, you have to make sure people can get the right care at the right hours.”
He said he did not blame GPs, who he suggested had been “demoralised” by budget cuts – adding that Labour would also seek to reverse closures of walk-in centres and ensure the non-emergency 111 helpline had more experienced medical staff.
But Health Secretary Jeremy Hunt said Labour’s figures were wrong, because they did not take into account the Prime Minister’s Challenge Fund, which covers 1,100 practices and helps 7.5 million patients see a GP in the evenings and at weekends.
“We are extending this scheme to cover over 1,400 additional practices, helping 10 million extra people by this time next year,” he said, adding that a Conservative government would deliver “a truly seven-day NHS”.
Pilot schemes paid for by this fund include those testing approaches such as the use of technology, health apps, and allowing access to services by video call, email or telephone.
Mr Hunt blamed Labour’s “disastrous” renegotiation of the NHS contract for GPs in 2004 for creating the problem, which Conservatives say “meant 90% of GPs stopped giving out-of-hours care”.
The Lib Dems also pointed to a £50m GP Access Fund, which they say helped 1,147 practices to extend their hours last year.
Party election spokesman Lord Scriven said: “The Liberal Democrats are the only party prepared to commit to spending the £8bn extra the NHS says it needs to survive.”
Meanwhile, Lib Dem leader Nick Clegg has been setting out how a crackdown on tax dodgers – and increased tax on shareholders’ dividend payments – would fund a rise in the personal allowance to £12,500.
The party wants to increase the point at which people start paying income tax to £11,000 next year, then to £12,500 by 2020.
Having spent much of Monday battling the Conservatives to claim credit for the increase in the threshold to £10,600 that had come in overnight, Mr Clegg continued his attack on his former coalition partners.
“The Liberal Democrats have got a plan to give further tax cuts to people on low and middle incomes by asking a little bit more from the wealthiest,” he said.
“The Conservatives… want to give tax cuts to the wealthiest by taking from the poorest. That’s the difference and that’s the choice which people have got when it comes to tax cuts at this election.”
PM on tour
Increasing the personal allowance to £11,000 would give 27 million people an £80 tax cut and take 376,000 people out of tax altogether, including 157,000 pensioners.
Both the Conservatives and the Lib Dems want to raise the threshold to £12,500, but the Lib Dems say they would implement the £1bn measure “far faster”.
Prime Minister David Cameron’s focus is on attacking Labour, as he embarks on a tour of the home nations.
Starting in Scotland before visiting Northern Ireland, Wales and England, he said he was delivering a simple message: “We have one month to save Britain from [Ed Miliband’s] mountain of debt; one month to save Britain from his punitive taxes; one month to save Britain, and British families, from his anti-business and anti-aspiration agenda.
“With every day that passes, the choice at this election becomes clearer and clearer. The election isn’t just a choice between parties; it’s a choice between two different types of United Kingdom. One that lives within its means – or one that heaps more debt on our children.”
Meanwhile, Mr Cameron has appealed for “frustrated” Conservative supporters considering voting for UKIP to “come home”, telling the Daily Telegraph the party had listened to their concerns over immigration, Europe and other issues.
But Mr Farage dismissed this, saying former Conservatives had “found a more authentic home where they don’t get abuse from their hosts”.
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