The scale of the task facing the Conservatives at the annual conference has been made clear by an opinion poll for ITV News.
It suggests that in 40 marginal constituencies where Labour and the Tories will go head to head, Ed Miliband's party has an 11% lead.
ITV News Deputy Political Editor Chris Ship reports on the lessons of history in the marginal seat of Dudley North:
A third of voters in 40 marginal seats would consider voting for Ukip at the next general election but over half said they would next cast their ballot for the eurosceptic party, a new ComRes poll for ITV News suggests.
In the event of a coalition government after the next election, voters would prefer the Liberal Democrats to Ukip as the junior partner by 42% compared to 35%.
Conservative voters also preferred to work with the Lib Dems instead of Ukip by 47% to 40%.
David Cameron is seen as a better Prime Minister than Ed Miliband among voters in key marginal seats, according to a new ITV News/ComRes poll.
This is despite the survey suggesting a hefty 11-point lead for Labour over the Conservatives in the battleground constituencies.
Close to half of voters (46%) said they would prefer Mr Cameron to remain as Prime Minister, against 33% who said they would prefer Mr Miliband.
ComRes interviewed a representative sample of 1,000 adults living in the 40 most marginal constituencies where the Conservatives and Labour shared first and second place between them at the last General Election in 2010.
A new ITV News poll shows Labour have a big lead in the battleground marginal seats that are key to next year's general election.
The ComRes survey found Ed Miliband's party were 11 points ahead of the Tories in the 40 tightest contests, a rise of five points since June.
Labour are currently on 41% in these seats, with the Tories on 30% - both sides were on 37% in these seats at the 2010 election.
ITV News Political Analyst Colin Rallings writes that a new poll suggests the Tories' two-pronged general election strategy is failing.Read the full story ›
David Cameron has pledged to build 100,000 new homes for young first-time buyers at discounted prices if the Conservatives win the next General Election in May.
Meanwhile, Labour has vowed to build 200,000 new homes a year by 2020 and said the Prime Minister has presided over the lowest level of house building in peacetime Britain since the 1920s.
Both the Conservative and Labour's housing pledges still fall short of charity Shelter's calls for 250,000 new homes to be built a year.
David Cameron has presided over the lowest level of house building in peacetime since the 1920s and that "fundamental changes" were now needed to the way the market works, the shadow housing minister said.
"Within weeks of taking office, he cut the affordable housing budget by 60%," Emma Reynolds said.
"After four and a half years he now tells us that he is going to deliver for first-time buyers but under his Government a record one in four young people are living at home with their parents and young people across the country are priced out of home ownership."
Labour MP Iain McKenzie was sacked as parliamentary aide to shadow defence secretary Vernon Coaker after he voted against military action.
Labour MP Rushanara Ali has resigned from the party's front bench in order to abstain from a vote on military action in Iraq.
She served as the shadow education minister and will continue to be the MP for Bethnal Green and Bow.
Ukip leader Nigel Farage is addressing delegates at the party's annual conference in Doncaster.
He has said that Ukip is now challenging Labour as well as the Conservatives, adding that "this party is not about left and right. This party is about right and wrong."
Mr Farage said that he had decided to choose Doncaster - where Labour leader Ed Miliband is an MP - to send a message that "we are now parking our tanks on the Labour party's lawn"