A £4bn investment in a major oil field off Shetland has been given the go-ahead. 

The Kraken field, which is estimated to contain nearly 140m barrels of oil, is majority-owned by Aberdeen-based EnQuest.

The construction phase of the project is expected to support 20,000 jobs.

EnQuest also expects to take on an average of about 1,000 operational jobs in the UK for each year of Kraken’s 25-year life.

The development, which was approved by the Department of Energy and Climate Change, is the largest investment announced in the UK North Sea this year.

Kraken’s two heavy oil fields will receive tax allowances introduced by the UK government in a bid to stimulate investment in the sector.

Chancellor of the Exchequer George Osborne said: “This is a big investment that will create jobs and boost the British economic plan.

“It is also evidence that our efforts to create a competitive tax regime that gets the most oil and gas out of the North Sea are working.”

Scottish Energy Minister Fergus Ewing also welcomed the announcement.

He said: “I had the pleasure of meeting with EnQuest in September this year and I warmly welcome this announcement of £4bn investment in the Kraken field east of Shetland and the job creation and supply chain opportunities it will bring.

“This follows on from a host of significant investment announcements recently – unequivocal evidence of the faith that the oil and gas industry has in the future of the North Sea as an oil producing province.”