A new report written by civil servants in Britain's government concludes that leaving the European Union would touch off a decade of uncertainty because of the complex process of agreeing to terms to leave.

The report cited in the Guardian newspaper on Monday said that millions would be affected as the UK takes a decade to extricate itself from the 28-nation bloc. The Guardian quoted the report as saying that "a vote to leave the EU would be the start, not the end, of a process."

The report argues it would take years to just negotiate new trade deals with the United States and others — causing uncertainty in the economy.

The comments come as members of the campaign to leave accuse their opponents of scaremongering.