15/04/2012 20:01 BST | Updated 25/04/2012 08:05 BST

Tony Blair Warns 'Charity Tax' Could Be Harmful Amid Widespread Concern

Former prime minister Tony Blair has weighed into the Charity Tax row which has engulfed the government in recent days, warning that ministers shouldn't be doing anything to discourage philanthropic giving.

Blair's intervention in a blog on The Huffington Post - ahead of a speech in Washington DC on Monday to the Global Philanthropy Forum - comes after a weekend which has seen dozens of philanthropists warn chancellor George Osborne his so-called "Charity Tax" threatens to curb the amount wealthy individuals donate to good causes in Britain.

It also comes as a poll of Lib Dem and Tory backbench MPs suggests most oppose the measure, which was included in last month's Budget.

The survey, commissioned from ComRes for the Charities Aid Foundation, questioned 71 coalition MPs over the Easter break amid claims the move will harm good causes. Of those, 46 agreed that charity donations should not be subject to the new limit with 15 supporting the policy and 10 not expressing a view.

A large majority (93%) agreed that the Government "should do all it can to use the tax system to encourage charitable donations from wealthy donors."

In his blogpost on Monday Blair writes:

This is absolutely the right moment for government to do all it can to promote philanthropy; and certainly nothing to harm it.

I have found working outside of the well-worn trammels of Government rewarding, inspiring and, potentially, with more influence than my time in politics. It is that reflection that makes today’s event and celebration of philanthropy so important.

Reflecting on his 13 year period in office, he concludes: "There are, of course, things that only Government can do and reforms only Government can enable. The profile of Government, however, as the sole means of effecting change and therefore the vehicle into which all efforts for change should be put, is misleading and wrong."

Sources close to Mr. Blair insist that the speech on Monday has been in the calendar for months. But his comments will enliven the running debate on whether ministers should U-turn on a policy which has been widely criticised by British philanthropists, charities and university professionals in recent days.

The Charity Tax is due to come into force next April, and would place a cap of £50,000 on the amount individual charitable donors can claim tax relief on.

It is thought to be heavily influenced by senior Lib Dems in the coalition, although George Osborne made a dramatic intervention into the debate last Monday, when he claimed that some of the charities receiving some donations "don't do very much," adding that he was shocked to find some so-called philanthropists paid little or no tax at all.

Ministers are said to be looking at alternatives to the Charity Tax, but the clock is ticking - with a prime opportunity to close down the row coming this week as MPs consider the Budget at committee stage in the Commons. An amendment to the Charity Tax could be passed during these series of votes.