Here are ten points — and the facts behind them — we think will come up during the debates:
The NHS as we know it can't survive five more years of the Tories
The Tories spent the last election promising to protect the NHS but broke their promise.
Waiting lists have grown to their highest for six years and one in four patients wait a week or more to see a GP.
The Tories have extreme spending plans which will mean the end of the NHS as we know it.
Cameron is a threat to working people's living standards
The Tories can't raise standards of living for working people because they believe Britain only succeeds when they help the privileged few at the top.
Wages are down by £1,600 a year since 2010 and energy bills are up £300.
The Tories always stand up for a privileged few
The Tories' first priority is always to help the privileged few at the top.
They said we were "all in this together", then gave millionaires a tax cut worth over £42,000 a year.
Millions of working people are paying more because of the Tories' VAT rise.
Their extreme plans could mean over 1,000 fewer Sure Start centres
Before the last election, David Cameron said he would protect Sure Start but since then there are hundreds fewer centres.
If they win the next election, they'd do it again. Their extreme plans mean over 1,000 of the remaining centres face the axe.
Labour will build a strong economic foundation
We'll balance the books and cut the deficit every year in a fair way by taking different decisions to the Tories.
We reject their plans for deeper spending reductions in the next three years than the previous five.
We'll raise living standards for working families
We will stand up for working people and take on vested interests like the banks and the energy companies to raise living standards.
We'll freeze gas and electricity bills until 2017 so that bills can fall but not rise.
We'll save the NHS
Labour created the NHS and it always falls to us to save it.
We'll invest £2.5bn to hire 20,000 more nurses and 8,000 more GPs.
We will guarantee GP appointments within 48 hours and cancer tests within one week.
We'll make sure the next generation can do better than the last
For the first time in living memory, people are worried that the next generation won't do as well as the last.
We'll cut tuition fees to £6,000, guarantee an apprenticeship for every school leaver and cut class sizes for 5, 6 & 7 year-olds.
You can't trust Nick Clegg
We all know Nick Clegg's rap sheet — but he'll be trying to hide it tonight.
We won't let him forget that he promised to abolish tuition fees, then trebled them.
We can't let him forget that he promised fairer taxes and then cut taxes for millionaires.
We will keep reminding him that he said he wanted to get rid of the bedroom tax, and then voted to keep it.
Nigel Farage wants to privatise the NHS
Nigel Farage and senior UKIP figures have repeatedly argued for going even further than the Tories on the NHS.
Nigel Farage says he supports a move away from the NHS as we know it to "an insurance-based system of healthcare".
This would end an NHS free at the point of use for all.