A re-cap on the day's main stories:

The Conservatives are to confirm they would spend an extra £8bn for the NHS in England by 2020

Labour said the Tories had made similar unfunded pledges

A senior Conservative source has told the BBC the party will pledge to raise the threshold for inheritance tax to £1 million

Labour leader Ed Miliband said the Scottish National Party's economic policies would have a "devastating" impact on the country and that taking full control of taxation would leave Scots with a £7.5bn "black hole" in their finance

The SNP leader Nicola Sturgeon said Labour were desperate and resorting to a campaign of "fears and smears"

That's all from the Politics Live team for tonight. We'll be back in the morning, from 06:00.

tweets: YouGov/Sun poll tonight - Labour have a two-point lead: CON 33%, LAB 35%, LD 8%, UKIP 13%, GRN 5%

Laura Kuenssberg
Newsnight Chief Correspondent

A senior Conservative source has told Laura Kuenssberg that the party's manifesto, to be released on Tuesday, will include a pledge to raise the inheritance tax threshold to £1 million. The pledge was in their 2010 manifesto but was blocked by the Liberal Democrats in the coalition negotiations.

Laura Kuenssberg also said on Newsnight that she had heard there could be a pledge to allow housing association tenants to buy their homes "at a real discount".

tweets: Tories will promise to raise inheritance tax threshold to £1m in manifesto next week, reports @bbclaurak, external#newsnight, external

BBC Radio 4

Earlier, the former Lib Dem leader Lord Ashdown drew a "hollow laugh" from the Greens' Caroline Lucas for saying his party regarded itself as "the green party in government".

The panel on Any Questions on BBC Radio 4 were talking about the suggestions that there might be a large reserve of oil under Sussex and Surrey.

Ms Lucas agreed that the present government had done better than previous ones on renewable energy, but said that was not hard and that it was not enough, particularly when it continued to extract too much fossil fuel.

BBC Radio 4

On the World Tonight on BBC Radio 4, there has been a debate about the part newspapers play in politics, especially at election time.

Bob Satchwell, the director of the Society of Editors, appeared with Natalie Fenton from the Media Reform Coalition.

BBC Radio 4

Panellists on Any Questions on BBC Radio 4 have praised the idea of people doing voluntary work, but there's been a keen debate about the Conservative's plan to allow people in bigger firms to take three days paid leave to work as charity volunteers.

Labour's Hilary Benn and the Lib Dems' Paddy Ashdown both raised the question of how the initiative would be paid for. Mr Benn said:

Conservative Party chairman Grant Shapps suggested that the benefits of people volunteering went to both the charity that was being helped, the individual and their firm. He said:

tweets: Saturday's i front page via @olyduff, external Tories fall in the polls #tomorrowspaperstoday, external#bbcpapers, external

Image source, i

Chris Cook
Newsnight Policy Editor

Will voters know enough before they cast their ballots?

Newsnight

For the course of the general election campaign, Newsnight each evening will be publishing an exclusive Newsnight Index on the likely outcome, based on a sophisticated forecast model. It is produced by Chris Hanretty from the University of East Anglia and his colleagues at electionforecast.co.uk. For more information on how the Index is produced, see here, external

Image source, bbc

David Cameron is to confirm plans for an extra £8bn for the NHS in England by 2020, if the Tories win the election. Labour says the "unfunded" pledge is a sign of a Conservative campaign in panic.

Campaigners for a more proportional voting system said the result in well over half of constituencies could be taken as read, almost four weeks before voters go to the polls. The Electoral Reform Society (ERS) said it could confidently predict the winner in 364 "safe" seats - 56% of the total 650 - because the UK's first-past-the-post arrangement meant resources were targeted at marginals.

Katie Ghose, chief executive of the ERS, said:

More than two thirds of the parties running in the general election are putting fewer than five candidates forward. Provisional figures from The Press Association suggest that of the 141 parties registered to run on May 7, 107 have fewer than five candidates, with 72 parties putting only one candidate forward.

The total number of candidates has dropped from 4,150 in 2010 to 3,963 in this election.