LONDON, Nov. 28 (Xinhua) -- The British government issued economic forecasts on Wednesday which showed that Britain could see a 3.9-percent drop in GDP over the coming 15 years under Prime Minister Theresa May's Brexit plan.

The 83-page report produced jointly by various departments across the British government including the Treasury modeled several different Brexit outcomes, and compared those with current growth in GDP.

The government did not provide a detailed cost of this type of Brexit, but British media reported experts estimating that it would have an annual debit effect of 100 billion pounds (128.3 billion U.S. dollars) 15 years from now.

In event of worst outcome, the No Deal Brexit, which would take place if Britain and the EU did not support the agreement reached between May and the EU, Britain's GDP would decline by 9.3 percent in 15 years' time than if the UK had remained in the EU.

Several Brexit outcomes were modeled in the government report. The report said under a Canada-style deal, the UK would be 4.9 percent worse off than remaining in the EU while the most favorable Brexit outcome was seen if Britain had frictionless trade and kept free movement of people, which would see the economy suffer just a 1.4 percent hit.

If Britain kept frictionless trade but restricted free movement of people there would be a 2.5-percent decline.