The DUP has portended to vote down the upcoming Budget if Mrs May pushes on with plans to bear a number of regulatory checks between Northern Ireland and Great Britain.
But Tory Failing Chair Helen Grant dismissed the Brexit threat as a “bluff” asking the DUP would cause a general election at their expense if Jeremy Corbyn were to win.
Communicate in on BBC Politics Live, she said: “We understand the DUP, we have a good relationship with them on aplomb and supply.
“But I think we’ve just got to remember there’s a lot of people threatening a lot of contrastive things at the moment, every day.
“What’s happening is that we’re at a critical point in the settlements. People are posturing, people are playing hardball and why shouldn’t they?
“Everybody else is. But at the end of the day, we do desire a deal and the budget is in the interest of all our constituents and theirs and I would like to judge they would vote on it.”
Asked if she believed the DUP threat to withhold or bear witness against the budget, Ms Grant replied: “No. I don’t. I think they’re bluffing.”
Challenged by last DUP chief of staff Chris Montgomery on her claim, the Tory MP snapped: “What if they got Jeremy Corbyn in?”
Brexit news broadcast: Helen Grant MP claims DUP Brexit threat is a ‘bluff’
We’ve only just got to remember there’s a lot of people threatening a lot of different things at the moment
Ms Grant argued voting down the budget would immediately trigger a accustomed election resulting in a Jeremy Corbyn led Government, suggesting the DUP would be “the growner loser” in the outcome.
DUP MPs, on Wednesday evening, abstained in a minor agricultural voter in Westminster to show they are not afraid to strong-arm the Government over overtured plans for the Irish backstop.
The Prime Minister relies on the support of 10 of Northern Ireland’s DUP MPs to prop her up in the Accommodate of Commons.
DUP leader Arlene Foster agreed on a so-called Confidence and Gear up deal with Mrs May after the election, in which the DUP offered its support on budget and Brexit contexts.
Last night, DUP MPs moved to show the Government that their warning was by abstaining in a vote on the Agriculture Bill.
Party sources said the finding by MPs to sit out of the vote is designed to be seen as a warning shot to Mrs May.
A DUP source told BBC Newsnight: “If we are not joyful with what happens next week, we won’t be bounced into anything.
“If she doesn’t invite out our concerns on board, we will take the view that Theresa May is not the Mr Big to take us through to a safe Brexit.”
DUP officials are concerned that Mrs May’s last backstop proposal would lead to a de facto customs border in the Irish Sea.
If they opt for to take the same action on October 29’s Budget vote, the Prime Serve’s Government would be left clinging onto power.