Labour has called on the Government to scrap the “reckless” Northern Ireland Protocol Bill to avoid “hitting the British people in their pockets”.

Shadow foreign secretary David Lammy told the Commons that instead of finding a solution over the summer, the Conservatives ramped up the rhetoric on the protocol, risking “new trade barriers with Europe”.

As Foreign Secretary, new Prime Minister Liz Truss angered the EU by tabling the Northern Ireland Protocol Bill, which would allow ministers unilaterally to scrap the arrangements the UK signed up to as part of the Brexit withdrawal agreement.

The European Commission has insisted such a move would breach international law.

During the Tory leadership campaign, there was also speculation that Ms Truss may move to suspend the protocol once in No 10 – by triggering a mechanism called Article 16.

Speaking in the Commons during Foreign Office Questions, Mr Lammy said: “We’re facing a cost-of-living crisis where bills are skyrocketing and people across the country will face the choice between eating and heating.

“Instead of proposing a solution, the Conservatives have spent the summer ramping up the rhetoric on the protocol to risk new trade barriers with Europe.

“Now this minister has had a recent elevation, will he take this opportunity to commit to scrapping the reckless Protocol Bill, so that it can begin serious negotiations with the EU to fix the protocol and avoid hitting the British public in their pockets?”

Europe minister Graham Stuart told MPs the first thing he did when he was appointed in early July was to read the protocol, insisting “it doesn’t matter how you look at it, it isn’t functioning”.

He said: “I thank (him) for yet again making so crystal clear both to the House and the British public that in any dispute he and his party will always side with the EU and not the interests of the British people.

“I’m horribly new to this brief, the first thing I did, the first weekend after my appointment, was to read the protocol, and it doesn’t matter how you look at it, it isn’t functioning, it isn’t working and for (him) and his party to suggest that it is us and not the EU that needs to change tack, all I would say is, yet again he betrays the British people and shows why Labour now and in the past and in the future is unfit for office.”

Later on, SNP foreign affairs spokesman Alyn Smith accused Ms Truss of using the plans to overhaul parts of the Brexit arrangements for Northern Ireland as a “vehicle” to win power.

He said: “The only way the Northern Ireland Protocol Bill makes sense to me, because it is wrong in international law, it is wrong in politics in that most MLAs support the protocol, it is wrong as a negotiating tactic because it has put backs up across the EU, there are ways of reforming the protocol within the protocol, but that has been ignored.

“The only way it makes sense was a vehicle for the future prime minister to prove how tough she is to Europe. Now is the time to get rid of it, as we have heard it is stymieing lots of constructive relations.”

Conservative former minister Steve Baker said the protocol “as it stands today has become a thorn in the side of relations between us and Ireland”.

He added: “Isn’t it time that we proceeded with the humility to recognise the legitimate interests of all parties to the protocol and also the fierce resolve to say enough is enough.

“It is time to solve the evident problems which have arisen and to evolve the protocol in a negotiated way if possible, but in any event to a solution which can last.”

Mr Stuart replied: “The protocol is not delivering the main objective set out on its face, that’s why something has to be done … I believe … that our clear preference for a negotiated solution is the right one, and I would further add of course that within the Bill is the facility to accelerate any negotiated agreement, and that is very much our offer to the EU.

“We’d prefer a negotiated solution, it’s very important to put this right.”

Meanwhile, DUP chief whip Sammy Wilson (East Antrim) said the protocol “has ripped apart the Belfast Agreement, it’s undermined democracy in Northern Ireland, it has increased costs to consumers and businesses, disrupted GB and Northern Ireland trade and displaced it with trade from the Republic, and is being cynically used by the EU as a mechanism to punish the UK for leaving the EU regardless of the cost to the people of Northern Ireland”.