Child Tax Credit and Working Tax Credit were introduced in April to replace Working Families' Tax Credit which many families relied upon to make ends meet.

Paymaster General Dawn Primarolo insisted on Thursday's programme the scheme was a "success".

However, one viewer from Leicester says she has been waiting six weeks to get emergency tax credits worth �400.

Meanwhile, the telephone lines to the Inland Revenue's tax credit helpline have been jammed for weeks and computers are down.

Still waiting

"I was offered a cheque last month but it still hasn't arrived," says tax credit applicant Caroline Cornwell.

"I waited 20 minutes to get through to whatever option you've decided and then they can't access your details because the computers are not rigged up for that sort of thing."

No joy: Caroline Cornwell

People first started hearing about the new tax credits in September last year when applications were invited.

The deadline for prompt payment was 31 January.

In April, weekly payments were due to start but by the middle of the month more than 300,000 people who had applied in time had not been paid.

Public apology

On 28 April Ms Primarolo was forced to apologise in the House of Commons.

In May monthly payments were due to start. However, at the moment 400,000 claimants remain unpaid out of the four million who have applied.

NEW TAX CREDITS

September 2002: applications for the credit were invited 31 January: prompt payment deadline April: weekly payments due to start 17 April: 300,000 people unpaid 28 April: Paymaster General apologises in parliament May: 400,000 claimants remain unpaid

Many claimants complain the money they have received is too small as tax credits have been calculated on income figures that are two years out of date.

Some say they have been left penniless as a result.

"I've got no money coming in. I had move out of the house I was renting and move back in with my mum," says Natalie Sanderson from Ashton-under-Lyne who has been trying to change her application details since February.

Information lacking

The Inland Revenue says that everyone who applied by the end of April has been paid but that excludes cases where more information is needed.

Sometimes people have said my details have entirely changed and we've had to go back and check them Dawn Primarolo

Profile: Dawn Primarolo

"We now have some five million families in payment, many of them receiving support for the very first time directly to the mother to help them with their child care costs and new couples without children are receiving money for the very first time," says Ms Primarolo.

"But in a new system there are clearly families who have not received... the service they were entitled to... and that we have to deal with as quickly as possible," she added.

Fraud concerns

She said parliament required everything to be cross-referenced - which takes time - to ward against fraud.

In some cases, National Insurance numbers have not matched.

"Sometimes people haven't put correct bank details... sometimes people have said my details have entirely changed and we've had to go back and check them," said Ms Primarolo.

She said Inland Revenue cleared 100,000 claims last week and that so far more than five million people have applied.

She said renewal of claims in the future would be much more simple.

Help line chaos

The call centres running tax credit help lines are overwhelmed.

"[People] are going on hold for half an hour to an hour and when they get through they get through... to an overflow department which cannot answer any of their queries whatsoever because they don't have access to their information," said a call centre worker.

Call centres have been overwhelmed

But Ms Primarolo said the worker must have been working for a private call centre which was brought in temporarily to help send out application forms.

She said Inland Revenue employees have access to the information but admitted demand placed on the call centres is still high.

When pressed on the issue of compensation Ms Primarolo said that in cases where people did not get the services they were entitled then she "would be considering their position".

Complaints will be dealt with through the Inland Revenue.

"My priority at the moment is to get the money out... then I need to reflect on what happened over the last couple of months and see what needs to be learnt... and make sure it works better next year."