Rock superstar Bono urged Tony Blair to lead the global fight against Aids and debt in Africa.

The U2 frontman brought a splash of glamour to the Labour conference as he arrived to outline the case for urgent help for the world's poor.

But his speech was delayed by almost an hour as a security alert prompted staff to lock the main auditorium in the Brighton Centre.

It is understood officials suspected members of the campaign group War On Want, who had been banned from attending, had sneaked into the auditorium and proceedings were delayed while they checked through photos of members.

A security official told The Argus: "The doors were shut because there was someone inside who shouldn't have been."

Officials from War On Want had been stripped of their passes earlier in the day.

Other officials from the group had their passes confiscated as they tried to enter the conference building in Brighton yesterday.

Campaigns officer Tim Peat said no reason was given by the security guard who took away his pass.

War On Want is part of a coalition involved in bringing Bono to address delegates.

The U2 frontman, introduced by broadcaster Tony Robinson, called on Tony Blair and Gordon Brown to use Britain's presidency of the G8 and EU next year to lead an international effort to tackle poverty.

The Dublin-based star, whose real name is Paul Hewson, praised Blair and Brown's work fighting African poverty but said much more needs to be done.

He told delegates: "You know as transcendent as I'd like to think a U2 show can be, it isn't life or death. This is.

"And I've met people whose lives will depend on the decisions taken by these two great men.

"They have great ideas. And the promises they have already made will save hundreds of thousands of lives - if they follow through."

Bono, who recently gave Mr Blair an electric guitar as a present, likened the Prime Minister and Mr Brown to Beatles John Lennon and Paul McCartney.

He told delegates: "I'm fond of Tony Blair and Gordon Brown. They are kind of the John and Paul of the global development stage in my opinion.

"But the point is, Lennon and McCartney changed my interior world - Blair and Brown can change the real world."

Bono was speaking as the conference's overseas guest, a role that in recent years has seen Bill Clinton, Nelson Mandela and Afghan leader Hamid Karzai appear.

To coincide with his address, international development minister Gareth Thomas announced an extra £3 million in government cash for a global fund to tackle HIV, malaria and TB.

The money was agreed by Mr Blair after a personal letter from Bono and Mr Mandela last week appealed for Britain and others to bring forward funds earmarked for next year.

Robinson, best known for his role as Baldrick in the BBC comedy Blackadder, said: "It was the speech conference needed to hear. Bono really laid down the challenge: We could make a huge difference to the lives of millions of people. In a way it was more important than any message coming out of conference this week."

Asked what Bono's plans for the evening were, Mr Robinson said: "I don't know but I should think there are at least 1,200 people here he'd be able to s*** if he wanted to."

Outside the hall, delegates described the speech as the best so far and most were unfazed by the singer's occasional use of mild swear words.

Tom Wright, from Sunderland, said: "Bono was incredible. For an outsider his depth of knowledge, experience and candour were superb.

"People might think the language was a bit fruity but it was the sort of thing you hear every day."