WHILE Tony Blair appears undamaged and emboldened by his backing for the war in Iraq, his Downing Street colleague Gordon Brown is facing a wobblier time over one of his proudest schemes.

The Chancellor's new system of Working Tax Credit and Child Tax Credit sets out to integrate the UK's tax and benefits systems, with the aim of ensuring that the correct benefits and taxes are paid.

That, at least, is the high-minded theory. On the ground, matters are looking much less clear.

On Wednesday this newspaper revealed that the Inland Revenue's £53 million Tax Credit Helpline had been constantly engaged for more than a week. Since then our newsroom has been inundated with calls and emails from anxious families who are experiencing severe problems with the new system.

Delays and incompetence appear to be commonplace. Many families who applied months ago are still in the dark over exactly what they are entitled to - and when the payments will be made.

One example of the kind of mistakes being made was to be found in New Earswick, where a 35-year-old woman was told that she was not eligible for tax credits - because she had a 33-year-old daughter. A clerical error had put 20 years on the 13-year-old girl.

This is one mistake, small in the scale of matters - but big to the family involved. And such errors appear to have been repeated across this region and around the country.

Computers are said to be to blame for this latest fiasco. We have been here before, of course - most notably after a new computer system caused chaos in the supply of passports. Now a struggling computer system is helping to undermine the Government's new system of tax credits, causing great worry to millions of families.

While technological problems arise in all walks of life, it is surely alarming that such an important plank of Government policy should apparently be undermined by malfunctioning computer systems. This unhappy mess needs to be sorted out immediately.

Updated: 11:37 Friday, April 18, 2003