THE father of a Royal Military Police officer killed in Iraq yesterday claimed that a huge political upset could be on the cards as he stepped up his campaign in Tony Blair's Sedgefield constituency.

Independent candidate Reg Keys said he was ready to "stand toe to toe and slug it out" with the Prime Minister after getting a boost through the defection of Labour stalwart Derek Cattell.

Mr Cattell, who was a member of Labour's Executive Committee in the County Durham constituency, quit the party to support Mr Keys' protest at the Iraq war.

The former GMB union regional officer said his conscience would not allow him to continue as a party member and that he could not vote Labour "through gritted teeth".

His decision to pledge support for the anti-war campaign has caused upset in the Labour Party, but Mr Keys said the move was indicative of the general feeling across the country.

Mr Keys' son, Lance Corporal Tom Keys, was one of six military policemen killed in an ambush in Iraq in June 2003.

At a news conference at his campaign headquarters yesterday, Mr Keys said: "Mr Cattell has done the honourable thing and I feel Tony Blair should follow by example.

"Such a catastrophic political blunder cannot merely be placed to one side - there has to be accountability."

Mr Keys also called on the Conservative and Liberal Democrat parties to withdraw their candidates to give him a clear run.

"We'll be looking to make a last-ditch appeal to the other parties - let Tony Blair and I stand toe to toe and slug it out."

Mr Cattell said: "I want to see a Labour Government returned to office, but I believe that such a Government would be strengthened with a new Prime Minister."

However, Mr Cattell was criticised for his move by Mr Blair's agent, John Burton.

In a strongly-worded response to Mr Cattell's resignation, he said: "It is a pity Derek did not contact me before this publicity stunt as I would have told him that I have known Tony for over 22 years and there is no one that I would trust more.

"Derek has always been on the extreme left of the party and has always been against most of what the Labour Government has done."

* Peace campaigners were last night preparing a campsite for hundreds of anti-war protestors expected to flock to the North-East to oppose the re-election of Tony Blair.

Members of the Blairditch Project travelled to the Prime Minister's constituency at the weekend to create a peace camp.

The group will hold a meeting in the Golden Lion pub, in Sedgefield, tonight at 7.30pm, with the Sedgefield Against War Group and candidates standing against the Prime Minister.