The 273,000 sq ft scheme has been in the pipeline for more than ten years.

The site has been cleared and Helical Bar said construction will now start in 2014 after a financial partner for the 19-storey project has been found.

The firm said: “At Mitre Square, London EC3, we have completed demolition of the existing buildings and anticipate starting the new building later this year, having identified a financial partner.”

Bidders believed to be interested in the scheme include BAM, Balfour Beatty and Skanska.

The announcement was contained in a bullish interim management statement by the developer this morning.

Chief executive Michael Slade said: “The London office development programme will provide the potential for substantial additional profit in the next few years.

“We continue to look for other assets to grow the investment portfolio and have a further £100m of firepower available to achieve this.”