Dave Prentis who will address Unison delegates in Glasgow at their conference this week has warned the Tory Government that its efforts to crush unions will fail, after a successful recruitment drive in newly privatised businesses.
Unison reports the loss of members following steep job cuts in the public sector had been all but made up for by new members recruited from businesses taking on public sector contracts.
Prentis has revealed that 170,000 new members joined Unison last year, including 4,400 in the week of the general election in May, while 180,000 had left the union after they were made redundant.
He also attacked proposed legislation making strikes unlawful unless 50% of those entitled to vote take part in a ballot, with a threshold of 40% support of everyone eligible to vote needed in public services.
Prentis said the move was vindictive and the union could mount a legal challenge, but he maintained the new law would make no difference to the unionâ€™s strategy on industrial action.
â€śIf the government is going to take away peopleâ€™s right to organise and protest it is a civil liberties issue,â€ť he said.
Unison has supported a succession of strikes over the last five years in protest at cuts in jobs, pay and pensions under a strategy Prentis said would need to undergo a thorough review.
â€śWe must review everything we do. It would be tragic to behave like first world war generals, leading people over the top only for them to be shot down. We must choose our battles carefully.â€ť
He plans to slim down the number of campaigns the union supports from the current 55 and link up with campaign groups to show how cuts in public service provision damage communities and abandon the most vulnerable.