Who’s going to “do a Portillo” this time round?

The Tories are aggressively targeting Ed Balls's seat

Closing the net

Few issues are more politically hazardous than immigration, but on the campaign trail it will be hard to avoid the subject. A recent YouGov poll of 57 marginal seats found that only the economy matters more to voters in these areas. The poll also found that 44 per cent of respondents in Labour-held marginals would be more likely (23 per cent much more likely) to vote Tory if David Cameron pledged to reduce net migration to 50,000 a year.

The Tory leader has said he would hugely reduce immigration: in an interview with Andrew Marr, he pledged a limit of "tens of thousands" per year, a level not seen since 1992. Immigration fell significantly during the recession (see chart), but net migration of 163,000 in 2008 indicates that Cameron would need to cut immigration by at least 38 per cent to bring the total to less than 100,000.

Cameron's populist promise may be unfeasible: he cannot limit immigration from within the EU, for instance. But Labour remains vulnerable. The Equality and Human Rights Commission reports that immigration from eastern Europe has depressed the wages of the lowest-paid British workers, and Jon Cruddas argues that Labour risks losing further ground unless it comes out in favour of a universal living wage.

George Eaton graph

Pair of Bristols

Trouble for the Tories in Bristol East, where the party's candidate, Adeela Shafi, is reported to have defaulted on nearly £325,000 of debt. The Insolvency Act 1986 and the Enterprise Act 2002 outlaw undischarged bankrupts from standing for parliament.

A spokesman for Conservative Campaign Headquarters refused to comment on the story. The loss of Shafi, a Muslim lecturer, would be a severe blow to Tory activists who have been running a prominent campaign to unseat Labour's "Twitter tsar", Kerry McCarthy.

Extracting the Michael

Michael Portillo's defeat at the 1997 election was so welcome that it was later voted the third greatest television moment of all time. Now the hunt is on for cabinet ministers whose defeat could provide this election's "Portillo moment". The smallest majorities are held by Jim Murphy and Alistair Darling (6,657 and 7,242, respectively). But both represent Scottish seats, where support for Labour is more resilient than in England.

Perhaps at even greater risk is Ed Balls, whose Normanton seat will be abolished. He will stand in the new Morley and Outwood seat, with a notional majority of 9,784. The Tories dismiss talk of a "decapitation" strategy but they are aggressively targeting the seat, hoping the ambitious Balls will demand the diversion of resources from other seats - potentially weakening those, too.

War is bad, Tories worse

What impact will Iraq's return to the political scene have on the election? As the only one of the three main parties to oppose the war, the Liberal Democrats have the most to gain from the Chilcot inquiry fallout, though Gordon Brown's decision to give evidence before the election has removed a useful line of attack.

Labour activists fear that anti-war voters will be angered by the inquiry and by news that Tony Blair may be involved in the election campaign. But in seats such as Bethnal Green and Bow, Muslim voters, many of whom abandoned Labour in 2005, are more concerned with preventing a Tory victory than they are with punishing the government further. Labour's rising ratings suggest voters may be prepared to forgive, if not to forget.