Lone parents and the long-term unemployed will face new pressure to get a job under reforms being unveiled today.

Work and Pensions Secretary John Hutton has insisted the changes are not intended to cut anyone's benefits.

However, campaigners have voiced concern single mothers and the mentally-ill will be forced into unsuitable jobs, after he confirmed the package will involve an element of "compulsion".

And unions warned of possible strikes at job centres after Mr Hutton said private companies and charities will be invited to bid for contracts to help jobseekers find work.

Proposals to reform the welfare-to-work system were to be contained in a Government-commissioned report by banker David Freud, which was being launched today by Tony Blair, Gordon Brown and Mr Hutton.

The Chancellor's appearance alongside the Prime Minister at the Downing Street launch was being seen as a signal the measures will remain at the heart of the Government's agenda after Mr Blair steps down this summer.

Despite record employment rates during Labour's 10 years in power, some 3.5million people remain on unemployment-related benefits.