Mr Hague said he believed the meeting would be useful, with some common ground on issues like the increase in interest rates.

William Hague: concerned how rate rises are affecting jobs

He said: "There are clearly a lot of issues on which we are not going to see eye to eye.

"But there will be some things, like the increase in interest rates last week and its impact on jobs and tax increases people are facing on which I think there may be a bit of common ground."

In a reference to the traditional image of trade unions, Mr Hague joked: "I don't know what's on the menu. I hope it's not sandwiches but I could do with a beer."

Mr Hague would have been relieved to discover that the dinner awaiting him was not sandwiches but was scallops followed by chicken, but he may have been disappointed to find the drink on offer was wine.

The last Tory leader to step inside Congress House was Sir Edward Heath in the 1970s.

John Monks: TUC invite

Mr Hague was invited to Congress House for dinner by TUC general secretary John Monks.

Other union officials at the meeting included Rodney Bickerstaffe of Unison, Bill Morris of the Transport and General Workers, Ken Jackson of the Amalgamated Engineering and Electrical Union, and John Edmonds of the GMB.

The TUC played down the significance of the meeting, saying it was a logical extension of the TUC relaunch in 1994 when the organisation decided it should foster links with all political parties.

Conservative ministers went to TUC conferences before the last election and Mr Monks has spoken at Conservative conference fringe meetings.

Civilised dialogue

However, TUC insiders acknowledged that the meeting was symbolic, and that it would be the first time some of the union leaders had met Mr Hague.

A TUC spokesman said: "We don't expect a great meeting of minds but we would like the Conservative Party to be like right-wing parties in other countries that have a civilised dialogue with unions even if they don't agree with them."

Bill Morris said: "We will be indicating to Mr Hague that we are concerned about the general insecurity in the workplace and we want to know what his policies are to deal with these issues and whether he will support the government on issues like the minimum wage, fairness at work and so on."