Former conservative prime minister John Major has issued a damning critique of those who want Britain to leave the European Union.
Writing in the Sunday Telegraph, Major derided the arguments which underpin the Leave campaign as "disingenuous" and "fantasy".
Major, the last Conservative prime minister before current incumbent David Cameron, said it would be "verging on the reckless" for Britain to leave the 28-member bloc.
His tenure from 1990 to 1997 was plagued by disputes within his party over Europe.
Major added those in favour of a Brexit were wrong to insist Britain could leave the EU and then renegotiate trade deals to its advantage.
"Their argument is that the EU needs the UK market more than we need theirs. This is at best disingenuous, more bluntly it is fantasy," he said.
Cameron has announced an in/out referendum on Britain's membership to the EU will be held on 23 June.
It comes after he agreed a package of changes to the UK’s membership with the bloc, following two days of high stakes talks with other member states in Brussels last month.
Major also argued that the UK already enjoys exemption from some of the more politically contentious aspects of European Union membership, such as the Schengen open borders agreement on free movement of peoples.
"It would surely be perverse to turn our back on these advantages and replace them with serious risks that alarm our international friends," he added.