The Iraq war has finally come to the fore of the election campaign with the defection of a veteran Labour politician to the Liberal Democrats.

Brian Sedgemore's call for voters to give Tony Blair a bloody nose over the issue has given new life to an old story. Parliamentary correspondent Daniel Bentley and Andy Tate ask how the controversial issue is going down on the doorsteps of Brighton and Hove.

Tony Blair has shared a common purpose with Basil Fawlty in the run-up to polling day.

"Don't mention the war" has become the mantra of Labour's bid for a third successive term in office.

But despite the relative success of this strategy in the early stages of the election campaign, the invasion of Iraq has been the source of renewed controversy this week.

It started with new evidence at the weekend that the Attorney General, Lord Goldsmith, warned the Cabinet in early 2003 the war "could" be deemed illegal.

This was followed on Tuesday by the surprise defection of outgoing Labour MP Brian Sedgemore to the Liberal Democrats, in opposition to the war.

Downing Street has turned a blind eye to candidates who are openly stating their opposition to the war, partly in an attempt to downplay it as a General Election issue.

Mr Blair claimed last week the May 5 poll would not be a referendum on the war and accepted he had not even won the argument within his own ranks.

He said: "There are going to be many people who vote Labour in this election who strongly disagree with Iraq."

"There are people in my own party - there are candidates for my own party - who disagreed with Iraq.

"There will be some people who will vote for other parties who agreed with me about Iraq."

On the streets of Brighton and Hove, Labour candidates are prepared to distance themselves from the decision to go to war.

For defending candidates Des Turner, in Brighton Kemptown, and David Lepper, in Brighton Pavilion, this is nothing new.

Both voted against war in March 2003, along with more than 100 backbenchers.

Hastings and Rye's Michael Foster abstained, only to resign later as a Parliamentary aide to Lord Goldsmith.

Today's visitors to Dr Turner's web site will find a personal statement setting out his view on the war.

He writes: "I have consistently voted against British involvement in the war on Iraq, but I would not want my negative views on British involvement in the conflict to detract from my support for British troops who are undertaking a very difficult job."

Celia Barlow, a newcomer to the national political scene as Labour's candidate in Hove and Portslade, has been prepared to cross the Government on this subject before she has even been elected.

She said: "I was not a supporter of the war in Iraq - my personal view at the time was diplomacy and international pressure were not given a fair chance."

But Ms Barlow stresses it is now important to tackle the "situation as it stands".

Her campaign aides say the issue is not the number one subject on the doorsteps of Hove and Portslade.

Most voters are more interested in issues such as the outcome of the Falmer stadium inquiry, they say.

But she is realistic that, should Iraq serve to increase support for anti-war parties, Labour's fragile majority in the seat could be wiped out.

Ms Barlow's views do not align with those of her predecessor, Ivor Caplin, who supported the war.

The junior defence minister endured the wrath of Hove and Sussex Action for Peace groups, who demonstrated more than once outside Hove Town Hall.

Meanwhile, Ms Barlow's opponents are happy to keep the focus on Iraq.

Liberal Democrat candidate Paul Elgood said: "The Lib Dems spoke for the nation in Parliament over concerns over the Iraq war and British troops should be brought home as quickly as possible."

Green candidate Anthea Ballam has said it was her opposition to the war that prompted her to stand in the election, adding: "We are totally against the war and have been from the beginning."

Paddy O'Keeffe, Hove and Portslade candidate for the anti-war Respect party, says the stances of individual Labour candidates towards the war are irrelevant as it was a Labour prime minister who took the country to war.

The Conservatives, having supported the invasion, are focusing instead on the issue of trust and are making noises about a speedy withdrawal of British troops from the war-ravaged country.

Hove and Portslade candidate Nicholas Boles, who supported the war despite reservations about the way it was conducted, said: "It's a good thing that we got rid of Saddam Hussein. We should get the troops home as quickly as we can."