The number of patients forced to wait more than six weeks for cancer tests has almost doubled in the past year.

Tens of thousands of people face lengthy delays for scans to pick up tumours, which could jeopardise their chances of recovery.

Campaigners warn that late diagnosis costs lives – and say it is one of the main reasons Britain’s cancer survival rates are so low compared with other Western countries.

Tests: Patients are waiting too long for MRI scans and ultrasounds – which are thought to be one of the reasons behind Britain’s low cancer survival rates

The latest monthly figures show that 5,700 patients were forced to wait more than six weeks for tests such as MRI scans and ultrasounds. this is a rise of more than 90 per cent compared with the same period last year.

They also reveal that the proportion waiting longer than six weeks has soared by more than 80 per cent since hospital waiting time targets were scrapped in July.

The Coalition said that the targets which stipulated any disease should be treated within 18 weeks of a patient seeing a GP had ‘no clinical justification’.

But experts point out that they put pressure for hospitals to carry out tests to detect bowel cancer, brain tumours and other serious illnesses early, allowing swifter access to treatment.

Department of Health figures show that in November 5,700 patients waited more than six weeks for diagnostic tests compared to just 3,109 in June, the last month before the targets were scrapped.

This is almost twice as many as during November 2009, when 2,900 waited at least six weeks.

Chemotherapy treatment: Problems are in the testing stage with patients on the NHS having to face too long to get fitted in

The figures cover 15 types of test including copcolposcopies and barium enemas used to diagnose bowel cancer, MRI and CT scans to detect tumours, and echocardiograms to track heart disease

Mike Hobday, of Macmillan Cancer Support, said: ‘If you diagnose bowel cancer early, nine times out of ten, you will live at least five years.

‘Diagnose it late, and only one in ten live that long.’

Only yesterday the Government pledged to save the lives of 5,000 patients a year by allowing GPs to refer people with symptoms of the disease directly for checks, avoiding the need to see a specialist.

Last month a report showed people aged 65 and over with some cancers are more likely to die than those in Australia, Denmark, Norway or Sweden.