The DUP has called for Prime Minister Theresa May to "exploit the chaos in Brussels and Dublin" and press for a better Brexit deal.
East Antrim MP Sammy Wilson, the DUP's Brexit spokesman, said it was time for the Prime Minister to take advantage of mixed messages coming from the EU and the Irish government over how to deal with the Irish border.
"Only last week, the Taoiseach claimed there will be no checkpoints along the border but then within a few days he was sending troops to guard installations which don’t even exist," he said.
"At the same time, Simon Coveney advised his Ministerial colleagues to say nothing about the border. He didn’t want to startle the Irish people. But whether out of panic or plan, Simon Coveney then raised the prospect of checks on boats at an unknown location.
"If the chaos in Dublin was not enough, the EU then weighed in and insisted one day that they will have Irish border checks and then the next day, promised there will be none.
"Now is the time for the Prime Minister to exploit the cracks which are emerging in the illogical position of the EU and the Irish."
The DUP has been at loggerheads with Mrs May over the proposed backstop, which would keep Northern Ireland in a customs union and the single market following Brexit.
Mr Wilson said the backstop would see Brussels "annex" Northern Ireland and undermine the Union.
"We always knew it would come to this when Brussels was faced with a situation of its own intransigence," he said.
"It is one of the reasons why the 29th March date must not be moved, otherwise the pressure which the EU and the Irish are now facing will be removed. Now is the time for the Government to be tough and to face down the stubbornness of Dublin and Brussels."
Mr Wilson added the EU views the Republic of Ireland "as a small country" which it will "toss aside" once it has been used.
Meanwhile, the DUP have been urged to "see the benefits" of the Prime Minister's deal by a delegation from the country's business, farming, trade union, community and voluntary sectors.
Twenty representatives held meetings in Westminster to stress the need for MPs to "unite and protect" Northern Ireland's jobs, consumers and economy - and they say the need for a Brexit deal is critical to avoid the UK crashing out of the EU in 60 days.
Labour's shadow Brexit secretary, Sir Keir Starmer, spent an hour talking to the group, which is also planning to meet Liberal Democrat leader Sir Vince Cable, SNP Westminster leader Ian Blackford and Brexit Secretary Stephen Barclay.
They have also invited Northern Ireland's 18 MPs to meet them.
Stephen Kelly, chief executive of Manufacturing NI, who helped organise the event, said the group wanted to "impress" on the opposition parties the need to protect Northern Ireland.
He told the Press Association that the group supported Theresa May's Brexit deal, and said: "Business in Northern Ireland and farming directly engaged with the negotiators to ensure that whatever came out of the Withdrawal Agreement was workable, and it is. So because we have been engaged and employed in the middle of that negotiation what we need is in that agreement, is in that backstop.
"If Parliament can't agree that, then whatever it agrees next needs to deliver exactly the same solutions, exactly the same outcomes as what's already been negotiated and agreed."
Asked what he would say to the DUP, who prop up Mrs May's Government, he said: "The DUP only partly represent what's going on in Northern Ireland.
"Business, farming and jobs all depend on a good agreement and we've been clear to the DUP and to others that we support this Withdrawal Agreement and we would encourage them to see the benefits of it for our community and our economy."
Glyn Roberts, chief executive of Retail NI, said: "It is not acceptable for Parliament to continue to create uncertainty.
"This is having consequences, as is apparent in our businesses and in our high streets.
"The actions of parliamentarians from across the House (of Commons) is not acceptable and I will be pleading with the leadership of the opposition parties that they need to reach across the chamber and avoid a calamitous crashing out of the EU which will have a dire impact on consumers and jobs."