Urgent action is being demanded on NHS pensions to stop the loss of staff in health trusts in Dorset.

A government change in rules for pensions contributions means consultants who agree to work overtime to reduce hospital waiting lists have been slapped with giant bills linked to the value of their pension.

The issue is a national problem with some consultants reported as having to re-mortgage their homes to pay the bills, whilst others claim the rules mean they have effectively had to pay their own money to work.

Patients at one Dorset hospital booked in for elective orthopaedic operations such as joint replacements could find them cancelled and deferred this month because of a national consultant crisis.

South Dorset MP Richard Drax raised the issue in the House of Commons, stating that experienced staff across local health trusts are declining to work overtime due to the crisis.

Mr Drax said: "People are warning of a workforce meltdown and, indeed, it would be difficult for a doctor to tell his or her family that he or she would voluntarily work overtime at the weekend in order to earn less. I understand that the average extra tax bill is £18,500 but there are reports of one off bills of up to £100,000.

"This is plainly madness. We desperately need our hospital doctors and GPs and senior nurses and indeed, our top administrators.

"I warned of this after my meetings with Eugine Yafele, CEO of Dorset Healthcare University NHS Trust, back in March. Then, we were finding that pension rules meant that older, more experienced staff were retiring too early, with a BMA survey showing that three quarters were citing these tax changes as a reason to retire.

"And now, the doctors we do still have are forced to work to rule. These are unintended consequences of the tax rules, undoubtedly, but they must be changed, and fast."

The issue was raised in the House of Commons following news of a 50 per cent rise in waiting lists for routine surgery – an increase which has been attributed to doctors working to rule to avoid these tax bills.

Responding to Mr Drax, Chief Secretary to the Treasury Liz Truss said: "Wide-ranging reforms to the taxation and pension systems are not things to be wished overnight; they have to be properly worked through."

She added that the government would consult the British Medical Association regarding the issue.

As many as 150 operations at Royal Bournemouth Hospital could be cancelled as a result of this situation, according to a leaked email.

Dorset County Hospital and Dorset Healthcare declined to comment.