TRADE unions seeking recognition rights will have to display support of at least 15% of the targeted membership in order to trigger a full ballot in which they must win a minimum 40% Yes vote under tough conditions expected to be agreed by the Cabinet today.

These guidelines from the Prime Minister's office are expected to be endorsed as the key elements of the forthcoming White Paper Fairness at Work, which is now due to be published within the next two weeks.

The unions, which had opposed the concept of an initial threshold and pressed for a simple majority of those voting, will be unhappy with these twin hurdles, although there will be a lot in the White Paper that they will appreciate, especially the setting up of an independent agency to adjudicate where there is disagreement over balloting constituencies.

Labour and the CBI, which argued strongly for an initial 30% threshold backed up by a minimum Yes vote of at least 50% and for employers to be allowed to dictate balloting constituencies, will portray the proposals as a compromise.

More outspoken union leaders can be expected to denounce them as falling way short of Labour's election manifesto commitment.