Upmarket London building firm Haymills, which worked on the restoration of the Cabinet War Rooms to their Forties style, today blamed majority state-controlled Royal Bank of Scotland for its collapse into administration.

Haymills collapsed this morning only to be sold straight away in a so-called pre-pack deal to French construction giant Vinci.

Administrator PricewaterhouseCoopers said the sale would save 430 jobs at the firm, which was founded in 1911. According to the company's website, it employs more than 700 staff.

It gave a statement to Construction News magazine blaming RBS for its woes: "As far as we are concerned, RBS reneged on a deal with us. An honest, hardworking company is in the situation it finds itself in because a bank owned by the people has reneged on an agreement," it was quoted saying.

The future of the business had been thrown into doubt last week when its Gibraltar subsidiary collapsed.

Haymills has in recent years carried out a host of high-profile projects in Chelsea and the West End. It traces its roots to the early days of the London underground, when it bought up and developed land flanking the then-new Metropolitan line.

PwC said: "This is a prime example of when a pre-pack sale can be the best option."

Administrator Stephen Oldfield said that, being a contractor, attempts to make a conventional sale after the administration appointment were "fraught with legal and operational difficulties which would have likely caused the business to collapse".

Vinci has been snapping up a number of regional British contractors in the past year. Last September, it bought Taylor Wimpey's contracting arm Taylor Woodrow for £74 million.