HOLYROOD ministers are prepared to go it alone in the UK as they seek to protect workers from controversial zero-hours contracts from any companies seeking public sector work.

Public procurement rules may be tightened to exclude firms involved in the practice from bidding for contracts with government agencies, councils and the NHS.

The Scottish Government yesterday said it was looking at options available to tackle the issue through public tendering. It cannot change employment policy, which is reserved to Westminster.

A survey yesterday estimated up to one million UK workers may be subject to the deals. They leave staff tied to a company but with no guarantee of their working hours when they report for work. Wider employment rights are also nullified.

Amazon, which has a depot in Dunfermline, Fife, has been criticised for freeing workers half-way through shifts when public transport is no longer running. Buckingham Palace, shops and private firms with public sector contracts have also used them.

A Scottish Government spokesman said it was "actively considering whether issues around the use of zero-hour contracts can form a legitimate consideration for a public body as part of the public procurement process."

He added: "The Scottish Government and its agencies do not employ people on zero-hours contracts."

A poll by the Chartered Institute of Personnel and Development has estimated the number of UK workers on such contracts as in excess of a million.

Labour's Finance spokesman Iain Gray said: "This survey raises the urgent question of how prevalent zero-hour contracts are in Scotland.

"If Scotland is in proportion to the rest of the UK, 100,000 Scots must be stuck on these contracts with no guarantee they will get work despite making themselves available to their employer."

Business Secretary Vince Cable is under pressure from Labour to hold a formal consultation to find out the extent of the contracts. He has so far only ordered a review.