DUP MP Sammy Wilson said his party has adopted a wait-and-see approach over what the UK Government will do about the Northern Ireland Protocol.
The party is refusing to say if it will nominate a speaker to allow the functioning of the Stormont Assembly on Friday, repeating its call for action to be taken over the protocol.
Foreign Secretary Liz Truss is to hold crunch talks with the vice-president of the European Commission Maros Sefcovic on Thursday, as ministers consider whether to override parts of the post-Brexit deal on Northern Ireland.
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Attorney General Suella Braverman is said to have approved the scrapping of swathes of the agreement, giving Prime Minister Boris Johnson legal cover to make the move, despite warnings from US president Joe Biden and European leaders not to single-handedly meddle with the terms.
On Wednesday, Mr Johnson said the Good Friday Agreement was more important than the Northern Ireland Protocol, as he dismissed suggestions of any possible escalatory response from the European Union as "crazy".
Mr Wilson said he will not welcome it "until we actually know what the Government intends to do, when it intends to do it, and what impact it is going to have".
Asked whether it is enough for the DUP to nominate a Speaker and ministers during the first sitting of the newly-elected Assembly on Friday, Mr Wilson replied: "Of course it's not, not until we see what is actually proposed.
"We have had these promises before and they haven't been acted on."
Mr Wilson told the BBC: "Ministers are approaching us on a daily basis now, indicating that the Government recognises that the protocol is causing a huge problem, that the EU are imposing the protocol in a way which was never, ever intended, and the Government is getting a bit fed up with that and are now prepared to do some acting.
"Let's face it, we have the implementation of the protocol in the most petty, draconian way by the EU, who are using it simply to teach the UK a lesson."
Sinn Fein has called for a new Stormont Executive to be formed immediately.
MLA Colm Gildernew was speaking following a warning by the British Medical Association and the Royal Colleges that political instability is putting basic service delivery at risk.
"All parties committed to making the transformation of our health service a priority, but health workers need more than commitments and promises, they want all parties around the table in an Executive meeting and working together to deliver," he said.
"That means investing an extra £1 billion into the health service to hire more doctors and nurses, tackle lengthy waiting lists and continue the transformation of health.
"And it means securing the first multi-year budget to ensure that much-needed transformation can begin.
"Sinn Fein is ready to form an Executive today, to nominate ministers and work with others to start the important work that people elected us to do last Thursday."
Alliance MLA Paula Bradshaw said: "The DUP's latest reprehensible power-play, designed to cover up its own failings during the Brexit negotiations as well as for the sake of personal expediency in the case of its leader, is putting thousands of our most vulnerable people at risk.
"The health service cannot be fixed without an Executive in place, taking steps to create a budget and manage work across all departments which will restore truly universal public health provision."
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