ARLENE Foster blasted Tony Blair and John Major for the “disgraceful” way they “used Northern Ireland” despite knowing what they were claiming was “not the case” during the Brexit referendum campaign.
The DUP leader, speaking at a conference on unionism in London, also said that Dublin's "very aggressive" Brexit stance has left unionists wondering if it is an attempt to claim Northern Ireland.
She said: “I do think it is quite disgraceful that they used Northern Ireland in that way, because they know that’s not the case.
“One of the most bizarre pieces around the referendum in Northern Ireland was when the Remain campaign sent Tony Blair and John Major to Londonderry to speak in favour of remaining in the European Union.
“If they thought that those two individuals were going to shift people to vote Remain - I thought it was quite bizarre.
“It is wrong for people like John Major, like Tony Blair to do all of that - very wrong.”
The DUP leader said Dublin's attitude had hardened since Leo Varadkar became Taoiseach last year.
She continued: "Our worry as unionists has been the very, very aggressive nature of the Irish government.
“That has been a change, it has to be said, from the last government, from Enda Kenny's government.
"It has been quite aggressive. And that leads a lot of unionists in Northern Ireland to think 'is this just about the European Union, or is it about something else? Is it about trying to claim the fourth green field in terms of Northern Ireland?'.
"As a unionist I see no logic or rationale for a hard border being created between Northern Ireland and the Republic of Ireland. The only people stirring up the myths of border checkpoints are those who are committed to unpicking the Union.
"They seek to use such imagery to advance and build support for their long term political objective.”
Mrs Foster added a "backstop" option of extending membership of the customs union, to allow for an alternative to be found, would need to be time limited.
The DUP leader added: ”There has to be a backstop on the backstop. It is vitally important that if that is to happen there is clarity in relation to the timing of it, for businesses in particular.
"We will not support a withdrawal agreement that creates a legal protocol with a new regulatory border down the Irish Sea."
Tory former Northern Ireland secretary Theresa Villiers also told the conference is was possible to avoid a hard border and leave the customs union.