Unions are concerned about the government's reform programme

It comes as Unison members prepare to vote on strike action over plans to contract out parts of the buying and supply arms of the NHS.

Delegates from Unison, the British Medical Association and the Royal College of Nursing will tell the Health Secretary to rein back on reforms.

But she is likely to say ministers are committed to their programme.

The delegation will say they have three major concerns - the pace of change, the direction of the reforms and the lack of consultation - at the meeting on Wednesday.

The private sector is driven by profits and it will lead to cuts in service Union official

In recent weeks the government has accelerated its progress towards a more market-based NHS.

Ministers have placed an advert in a leading European journal asking firms to put forward offers to take on the commissioning responsibility from local health bosses.

Critics believe the move will create a potential conflict of interest with private firms in charge of buying care from private hospitals and GP services.

And on Tuesday, Unison announced it would ballot its members over the transfer of supply agency, NHS Logistics, and part of the buying organisation, the NHS Purchasing and Supply Agency to a US / German consortium of Novation and DHL.

'Not finalised'

The move will mean almost the entire responsibility for buying and distributing everything from medical equipment to food to hospitals and family doctors will be handed over to the private sector.

Health Minister Andy Burnham said the plans were not finalised yet, but the move could save the NHS money which could be "reinvested into patient care".

But a union official close to the talks said delegates will tell the Health Secretary she threatens stirring up anger among the NHS workforce over increased use of the private sector and reforms to make the NHS more competitive.

"The government seems set on handing the NHS over to the private sector bit by bit and as long as they can say it is free at the point of use they believe it is okay.

"Well it isn't. The private sector is driven by profits and it will lead to cuts in service."