Thousands of taxpayers rushing to file their tax returns before tonight’s midnight deadline for self-assessment are being frustrated by delays to the Inland Revenue’s website.

The Revenue admitted that its heavily promoted online service appears to be struggling to cope with "very heavy traffic" as taxpayers try to avoid the £100 fine for late returns.

A spokesman for the Revenue said the system had not crashed but "some people have been experiencing difficulty getting through."

The spokesman added that the Revenue had increased the site’s bandwidth to cope with the demand but he offered little sympathy for taxpayers struggling to submit their returns.

"People have had since April to file their returns," he said. "The service is available throughout the tax year, so the moral is: ‘Don’t leave it until the last minute to file your return’."

Last week a record 34,000 people a day were filing their tax details online and many more were expected to try over the weekend and today.

Despite the popularity of the online service, nearly one million taxpayers are expected to miss today’s deadline, meaning the Government will raise approximately £40 million in fines.

When Times Online visited the self-assessment website, it appeared to be working albeit at a very slow pace. Each page took between ten and 30 seconds to load. The self-assessment helpline has also been engaged all day.

Readers who contacted Times Online complained of other problems.

"I wish I had got as far as having problems with the website," Alan Thompson told us.

"Over two weeks ago, I went online to apply for an access code, which is sent out via post, to allow secure use of the site.

"But after seven days I had received nothing so I called to find out what had happened. When I eventually got through, I answered one of the security questions wrongly because I had recently moved house and changed telephone numbers.

"They wouldn't let me try again as it was a one strike and you're out policy so I was denied help and told the best thing to do was to print out the form and do it by hand."

Meanwhile, union leaders have warned that plans to axe thousands of jobs at the Revenue could lead to more errors and delays in dealing with tax returns.

The Public and Commercial Services union (PCS) said the Government could be "storing up trouble" by slashing 10,000 revenue jobs as part of a huge civil service cutback.

The Inland Revenue is to merge with Customs and Excise under plans to cut more than 100,000 jobs in the civil service over the next few years.

PCS national officer Frank Campbell said: "Over the coming weeks we will begin to see just where the axe will fall in the Inland Revenue and Customs. Our fear is that this could be the last self-assessment deadline to pass off without a hitch.

"As jobs are cut, together with the possibility of local tax offices closing, it will become harder for people to get the correct tax advice in order to file their returns on time. The effect will be more errors and delays."

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