Tony Blair has proposed tougher new immigration rules as a solution to Brexit.
The former prime minister has put his name to a report that calls for tighter domestic controls and the negotiation of modified free movement rules with the EU.
He said this approach would fulfill the will of the people expressed in last year's Brexit vote while allowing Britain to stay in the EU.
Mr Blair's intervention appears designed to provoke a fundamental shift in the Brexit debate and solve the seemingly intractable trade-off between the economy and immigration.
In an article for the Sunday Times website, Mr Blair said: "There is no diversion possible from Brexit without addressing the grievances which gave rise to it.
"Paradoxically, we have to respect the referendum vote to change it."
He went on: "We can curtail the things that people feel are damaging about European immigration, both by domestic policy change and by agreeing change within Europe."
Mr Blair said the open doors he presided over were no longer workable.
He said: "Back then the economy was strong, the - workers needed."
But Defence Secretary Sir Michael Fallon has told Mr Blair to "get over it" and accept that Brexit is happening.
"It's a bit late now this epiphany, I'm not sure where he's been - well we know where he's been, he's being travelling the world.
"The country wants proper controls over immigration, we saw that in election after election and we saw that in the referendum last year.
"The country has taken it's decision, we're leaving the European Union now, and that means freedom of movement has to end whether we like it or not."
Meanwhile, Tory grandee Lord Heseltine criticised "damaging" government proposals revealed in a leaked Home Office document this week.
Addressing the Home Office plans in the Mail on Sunday, he wrote: "Free movement of labour would end immediately and all but the most highly skilled EU workers deterred from coming to this country.
"I fear the very social fabric of our caring society, health services and swathes of the public sector which depend on immigrant support could be destroyed if this happens."