The Government was today urged to legislate to stop companies ending or diluting occupational pension schemes.

Unions have become alarmed at the number of firms announcing an end to final salary pension schemes.

The plea from trade union Amicus came amid warnings of a "silent revolution" in the world of work.

Amicus said if measures were not taken to protect occupational schemes, future generations of workers would face "certain poverty" in their old age.

General secretary Roger Lyons said in a letter to the Prime Minister that there was an accelerating trend away from final salary pension schemes, often leading to a substantial cut in employers' contributions.

"There is a silent revolution going on in the world of work. Employers are turning back a century of progress in pension provision."

He called on the Government to strengthen workers' rights to a decent occupational pension.