Britain is to write off hundreds of millions of pounds in debts owed to it by some of the world's poorest countries.

UK Chancellor Gordon Brown is preparing to announce debt relief to around two thirds of the world's 41 poorest nations.

In return for the countries promising that the money will not be spent on arms or bureaucracy, debt will be relieved on a case-by-case basis up to 100 per cent.

In an interview for Saturday's Guardian newspaper, Mr Brown suggested that at least 25 countries would receive help with their debt burdens during the coming year.

"We have got to get the debt relief process moving," he said.

"We are determined to use whatever energies we can to put pressure on the international community."

He said his discussions with other European leaders led him to believe that other countries might follow suit and grant debt relief.

Jubilee 2000 - the campaign group to end third world debt - called the move "wonderful news".

Spokeswoman Ann Pettifer said: "It isn't a great deal of money, but it is politically very important.

"We need to persuade Japan, and France and Germany to do the same and then it will start to make a real difference to those poor countries," she added.

Details of the scheme will be laid out by Mr Brown and International Development Secretary Clare Short at a seminar with aid agencies and church leaders on Tuesday.

It follows a lead already given by the United States.

Celebrities hail move

The campaign to end third world debt has been bolstered by high profile campaigners from the world of music.

Former pop star Bob Geldof, a leading campaigner, said he was "thrilled" by the decision.

"It's an amazing thing to do, and frankly we will not be remembered for wheels and Domes and fireworks," he said.

"I think future generations will remember a very simple and confident gesture like this," he told the BBC.

Mr Geldof praised Mr Brown. "For him as a man, personally, I think it must be a great thing for him to be able to do," he said.

But he also urged the government to do more. "I believe there are conditions attached," he said.

"The countries have to apply through multilateral institutions, and when they have gone through the process which will take about a year, then on a case by case basis they will be forgiven the debt."

He called on the government to allow countries to put interim debt payments into a trust account which they should have refunded after a year.

Bono, of Irish rock band U2, also expressed his joy at the announcement.

He said: "I am absolutely delighted. Tony Blair and Gordon Brown will be remembered for this."

Programme begins in January

A Treasury spokesman confirmed that following discussions with the World Bank, the IMF and other countries, Britain was ready to forego debts owed by countries qualifying for the recently revised international Highly Indebted Poor Countries (HIPC) Initiative.

Mr Brown and Ms Short will announce that by the end of January 2000, the first four countries should start to enjoy the new relief.

By August, that figure is expected to rise to 10 countries and the government's target is that by the end of the year the figure should be 25.

The shadow international development secretary, Gary Streeter, welcomed the government's move.

He said: "We have been calling for the complete cancellation of the bilateral debt to the world's poorest countries since President Clinton took the lead on this in September.

"The most important thing now is to cut through the red tape and deliver the debt relief quickly so that the poorest countries can invest in health care and education."

Oxfam's policy director Justin Forsyth said Britain had "shown the way" on the issue, but had some reservations.

He said: "The fear is that those who were opposed to debt relief like the IMF, like some countries like Japan and Germany, will now make this a very slow and tortuous process. We need to keep the momentum up."

Should other countries follow suit?