Unions demand compensation for Bovis and Skanska workers as Treasury and MoD sites are cordoned off.
Construction projects in central London were due to be closed on Thursday as part of the security operation for the visit to the capital of US president George W Bush.

The Metropolitan Police carried out one of its biggest operations ever when Bush flew into Heathrow airport on Tuesday night, before flying by helicopter to have supper with the Queen and the Duke of Edinburgh at Buckingham Palace.

Key government construction sites were to be closed on Thursday, when a large anti-Bush demonstration was due to take place. The sites included the Treasury building site, where Bovis is main contractor, and Skanska's Ministry of Defence building. Government officials wanted the sites to be closed to restrict access to construction equipment that could be used as weapons during the protest.

The decision to close the sites for a day came as unions put pressure on contractors to compensate workers and subcontractors for their losses.

A Bovis spokesperson said that work would stop on the Treasury project for the whole of Thursday. He said the decision had been made because the site would be cordoned off and deliveries would not be able to get through. He added that Bovis would ensure that nobody was out of pocket.

Bovis said it was also reviewing security measures at its BBC development in White City, west London, and the West 8 office project in Regent Street in the West End as part of contingency planning for the protests.

A Skanska spokesperson confirmed that its site would be shut for the duration of the protests.

She said: "Skanska will be compensating its employees and trade contractors for the costs of the stoppages."

A Ministry of Defence spokesperson would not comment on issues surrounding security, but said that if any site stoppages occurred contractors would be compensated.

It was expected that more than 100,000 anti-war and environmental protesters would march through the capital to mark Bush's visit.

The centrepiece of the anti-Bush protest was due to be held on Thursday afternoon. Protesters were due to march from Mallet Street through Whitehall to Trafalgar Square, where a rally was to be held in the evening.