Tens of thousands of patients face potentially fatal delays in receiving the best drugs for their diseases because of Government cuts, it was admitted yesterday.

Almost a quarter of the treatment appraisals being carried out by the National Institute for Clinical Excellence (Nice) have been delayed because it has had to scrap one of its three committees carrying out assessments.

Andrew Dillon, the chief executive of Nice, told The Daily Telegraph that, since the Government had cut funds by £3.5 million, the backlog of appraisals was much bigger than had been disclosed so far.

The delays could be a matter of life or death for patients with diseases such as breast, colon and pancreatic cancers waiting for decisions on whether more effective treatments are to be available.

Of the 63 appraisals being carried out, 15 have been delayed by up to an extra four months. This means that patients in England will not have access until late in 2007 to treatments available in Scotland and abroad.

Mr Dillon said: "When it became apparent that money was not coming, the third committee became unsustainable. Not having that committee meant that we had to put back the publication date of around a dozen appraisals."

Doctors can prescribe a drug when the Medicines and Healthcare Products Regulatory Authority has licensed it. But in practice it is rare to get NHS funding until Nice has made a recommendation.

Patient support groups are worried that the number of new treatments unavailable to NHS patients because they are awaiting Nice approval is bigger than ever before.

The number of appraisals awaiting decisions is 63, compared with 29 four years ago.

Drugs that have been shown to improve patients' chances of survival and that have been delayed because of the cuts include Arimidex and Letrozole for early breast cancer.

Decisions on whether to fund Irinotecan, Bevacizumab and Cetuximab for advanced colon cancer, Cetuximab for head and neck cancer and Gemcitabine and Rubetican for pancreatic cancer will also take longer.

The same goes for 15 appraisals for treatments for conditions such as hepatitis C, heart disease, diabetes, lymphocytic leukaemia and age-related macular degeneration.

Nice took over the functions of the Health Development Agency in April. The 2004-05 budgets for the two organisations were £19.6 million and £14 million respectively. The new combined budget for this year is £29.2 million, an overall cut of £4.4 million.

The Scottish Medicines Consortium has been able to reach decisions on some drugs up to three years earlier than Nice.

Rituximab (Mab Therma), a drug that slows the progression of non-Hodgkin lymphoma, was approved for Scottish NHS patients last December.

Nice is not expected to make its recommendation before September 2007. A similar time difference is expected for the use of bortezomib for relapsed myeloma (malignant bone marrow tumours).

Mr Dillon said it was wrong that English patients should have to wait so much longer than those in Scotland.

"There are differences in the Scottish process," he said. "However, patients would say, 'I don't care about the distinctions between bureaucratic processes; I want to know why it is different in Scotland.'

"My response to that is: fair enough. We must make it so that it is the same or that the differences are small."

Nice's budget has grown from £9 million when it was set up in 1999 to close to £30 million this year.

Mr Dillon said that, while more money would lead to quicker decisions, he accepted the Government's desire to focus resources on front-line services.

He added that Nice was considering introducing a fast-track appraisal process that would halve the current time for simpler, more clear-cut cases.

"If you add a third committee, that widens the neck, if you see this as a funnel. The wider the neck of the funnel, the more rapidly the appraisals are going to go through.

"But periodically you get to the point where you say we are going to have to improve quality and volume by being better at what we do.

"We have to see whether there are circumstances in which we can run a more rapid appraisal than the standard 14-month one."

Joanne Rule, the chief executive of the charity CancerBACUP, said: "The length of time it takes for any drug to go through Nice is a life or death issue for cancer patients.

"A fast-track system is urgently needed for those cancer drugs which are recognised as potentially increasing survival rates.

"The Government should consider setting up a separate advisory group to examine new cancer treatments within three months of a licence being granted then recommend which ones should be fast-tracked through Nice."

The Department of Health said that Nice originally had two appraisal committees and that a third was added in the expectation of an increase in the number of technology appraisals referred to it.

"In fact, such referrals have not increased as expected at the time," a spokesman said. "Our understanding is that Nice has concluded that the third appraisal committee is no longer essential."