BOB GELDOF will use his annual visit to the Hay Festival to hit back at his critics tonight, when he appears in public for the first time since announcing the Live8 concerts this summer.
He will make an impassioned plea about the urgent need for people in Britain to help the poverty stricken in Africa, but is also expected to tackle claims he was irresponsible when he called for a million people to march to Edinburgh to protest.
The Live Aid founder also said children should bunk off school and people should get to Edinburgh anyway they could to show the strength of feeling ahead of the G8 summit later this year.
Scottish police chiefs have warned such a huge protest could be dangerous and could end in tragedy.
But Geldof's calls yesterday won the backing of Chancellor Gordon Brown, who said it should go ahead as long as it was peaceful.
"We are going to support people who want to make their views known," said Mr Brown. "I think we want a peaceful demonstration. People have a right to make a peaceful protest and that is something people should be able to do. But it must be peaceful, and I think everybody in Edinburgh wants to see that happen."
Geldof said he was confident Edinburgh could cope with one million people descending on the city.
"Edinburgh gets this figure every year at the Edinburgh Festival. It is a hugely sophisticated city that is able to take large amounts of people," he said.
The Live8 events are intended to raise awareness of world poverty and put increased pressure on the G8 to cancel Third World debt, increase aid to developing nations and promote fair trade.
An international series of concerts will be backed by a march to Edinburgh on July 6, the eve of the summit of the G8 - the group of the eight leading industrialised nations - at Gleneagles.
The events are taking place in support of the Make Poverty History campaign, a lobbying group comprised of hundreds of UK charities and trade unions.
But Geldof was last night warned that his efforts may be in vain, as the USA is reluctant to sign up to any agreement.
Glenys Kinnock, Labour's international development spokeswoman in the European Parliament, warned that America was fundamentally opposed to key elements of Gordon Brown's aid programme. She said she was not optimistic that an agreement could be reached.
The Chancellor yesterday promised to effectively write off the £500,000 VAT bill for the Live8 concert in London's Hyde Park on July 2.
He said, "We are going to waive the bill for the cost of the concert and waive the bill for the cleaning up.
"That is in lieu of any payment of VAT. That is a way of helping this event - probably worth about £500,000."
The move mirrors Mr Brown's decision to make a payment in lieu of the VAT on the Band Aid Christmas single.
Geldof was booked at the festival to launch his new hardback book, Geldof in Africa, which is packed with his thoughts on his trips to the continent's trouble spots as well as harrowing images of him with the poor who live there.
In a foreword he writes, "The whole of the last year has, for me, been focused on Africa. You would think I would be sick of it by now. I'm not. Because I believe we are finally on the brink of helping to change the situation of extreme poverty for the better. And I want to help do that."
Geldof, a friend of Hay Festival director Peter Florence, is a regular at the annual event, but usually sticks to musical themes.
"We have been celebrating Bob as a musician for many years so it will be nice to recognise his global political interests," said Florence.
"He will be talking about his travels to Africa, what the West needs to do to help Africa and the pressures we, as voters, can apply to try to persuade our politicians to try to do something about Africa at G8.
"As this is his first public speech since the Live8 announcement, I am sure he will also be taking questions about it."
Florence said he was delighted that Geldof would be launching his book at the festival.
"He has been a mate for a long time so it's wonderful to celebrate him. I admire him hugely and think he is a vital and exciting part of British life."
Later this year, Hay Festival organisers will work with Geldof in helping to organise a Live8 conference.
"We don't know exactly when it will be yet but it will involve creative thinkers, scientists and environmentalists talking about the problems relating to Africa."
Before Geldof takes to the stage tonight, one of the Live8 performers, Sting, will also be speaking to visitors at Hay.