Nearly half of trade union members are against joining the euro, according to a new poll seen by today's Times.

The poll, carried out by ICM for the "No" campaign, indicates that only 22 per cent of members believe the TUC should campaign for Britain's entry into the single currency.

The delegates at the Trades Union Congress are to debate a motion on Wednesday which promises "positive support" for a "yes" campaign in a referendum.

Dave Prentis of Unison said that joining the euro would lead to spending cuts which would be a "disaster for our public services."

The poll comes as the Institute of Economic Affairs warned over the weekend that joining the Euro would be against Britain's economic interests.

However, research by economists in Washington suggests that the creation of the euro has significantly boosted trade between euro-zone countries.