John Reid, the Secretary of State for Health, mounted a last-minute arm-twisting exercise yesterday to limit the scale of defeat in the vote on foundation hospitals.

Party leaders are resigned to losing today's conference vote on their plans to give greater independence to top-performing hospitals.

Union leaders are certain to vote as a block to support a motion from Unison, the public service union, that said the proposals spell the end of the National Health Service.

The weight of the union vote will result in an overall conference defeat for the foundation hospital plans but ministers hope most constituency delegates will support the Government. Such an outcome would enable ministers to argue there was grassroots support for the move.

Mr Reid met groups of 20 delegates at a time, urging them to oppose the Unison motion. In the meetings, he is understood to have argued that the opposition is "all about producer interest, trade union interest". He insisted that the Government was responding to consumer pressure.

One delegate who met the Health Secretary described the session as an "indoctrination meeting". She said that some people might feel "intimidated by all this pressure".

Mr Reid has argued that the foundation hospitals plan has been driven by the needs of voters who now expect choice in health treatment. He has risked antagonising union leaders by portraying them as out of touch with public sentiment. He will tell the conference today that the plan is aimed at "enabling the NHS to respond to the differentiated needs of 60 million people. They are the people that matter".

One aide said last night: "We will lose the vote, but win the argument."

A Unison spokeswoman said: "This isn't about the union block vote, it's about winning the hearts and minds of people to our point of view. We want to provide the very best health service so patients come first."