Midnight approaches, meaning it's time to wrap up today's Politics Live blog. Here's a recap of the day's big political developments:
- Downing Street has declared David Cameron will only participate in one leaders' debate - and ruled out a head-to-head with Ed Miliband
- Labour, the Liberal Democrats and UKIP have criticised the prime minister's stance
- Fresh polling from Lord Ashcroft indicates the SNP are on track for substantial gains in Scotland - including taking Labour's safest seat
- The SNP's Alex Salmond has reaffirmed his party's interest in a deal with Labour and declared his party is enjoying "massive support" north of the border
- The debate over immigration has continued after Nigel Farage's speech and Ed Miliband's focus on the issue in PMQs
The campaign countdown continues tomorrow from 6am GMT - join us then.