Emergency legislation is needed to assert “beyond doubt” the UK “controls our own borders”, Tory MPs have said, amid claims over EU influence in Northern Ireland.

The UK Government has vowed to appeal a Belfast High Court ruling, which stated that provisions of the Illegal Migration Act should be disapplied in Northern Ireland as they undermined human rights protections guaranteed in the region under post-Brexit arrangements.

Mr Justice Humphreys also said aspects of the Act were incompatible with the European Convention on Human Rights (ECHR).

But some Conservative MPs raised questions over the merit of an appeal and instead suggested the Government should legislate in Westminster to correct “defective” law.

Conservative former home secretary Suella Braverman told the Commons: “In the decision, the judge found that section 7(a) of the Withdrawal Agreement Act, as amended by the Windsor Framework, must be read to mean that Northern Ireland is effectively to be treated as part of the European Union.

“I believed the assurances made to me at the time, but isn’t it now patently clear that the Windsor Framework has operated in a way to undermine our sovereignty, to undermine Northern Ireland’s place within the United Kingdom and I’m afraid has fundamentally failed upon its first contact with reality.”

Home Office minister Tom Pursglove said there should be “consistent application across the UK” of immigration policy.

Conservative former minister Sir John Redwood said: “We voted in a referendum to end the rule of EU law throughout the United Kingdom, including Northern Ireland.

“Isn’t the only way out of this – given the muddle the courts are creating – is to have an urgent, short piece of legislation which asserts beyond doubt that we control our own borders?”

Sir Christopher Chope, Tory MP for Christchurch, said: “Why is it that the Government is not going to directly legislate to deal with this situation – that the legislation is defective. If we go to appeal and we find the appeal is rejected then we’ve lost a lot more time.

“Why don’t we act now to legislate and sort out this mess?”

Mr Pursglove said the Government was taking legal advice in relation to the judgment, adding: “It would not be right to give a running commentary on the substance of that.”

Conservative former minister Mark Francois said: “On the Windsor Framework, we told you so. On the judgment itself, legally all roads lead not to Rome but in this case to Strasbourg and the European Convention on Human Rights.”

Mr Francois said the convention was drafted for “perfectly honourable reasons” in the aftermath of the Second World War, adding: “It’s now clearly been overtaken by events and international migration flows.

“So hasn’t the time now come for a Conservative Government to include in our election manifesto a clear commitment to seek to renegotiate this convention with our European partners, but should those negotiations fail, to leave – because if we aren’t prepared to walk away, they will never take us seriously.”

Mr Pursglove, in his reply, said: “For illegal migrants, all roads lead to Rwanda and for the people smugglers responsible for this evil criminality, all roads lead to prison.”

DUP MP Sammy Wilson (East Antrim) warned that the Government’s immigration policy risked hastening the day when “people controls” existed between Northern Ireland and Great Britain.

He said: “The Government can make as many appeals as it wants, as many promises from the despatch box and as many agreements about safeguarding the Union, the fact remains that because of the pathetic handover of Northern Ireland to the EU, the judge made it clear yesterday that EU law now extends and has to be applied in Northern Ireland.

“The result is, we have another hole in the Government’s immigration policy, a national immigration policy now dictated by the EU. Northern Ireland will become a backdoor in the United Kingdom and it’ll hasten the day when we will have people controls between Northern Ireland and GB as well as goods controls.

“Does the minister recognise that unless we remove the source of this – namely the commitments in the Withdrawal Agreement – this will continue?”

Mr Purslgove replied: “I don’t think there’s any question whatsoever of any merit in the suggestion that the UK would hand Northern Ireland over to the European Union.”

Mr Pursglove earlier told MPs: “When it comes to some of the concerns that I know have been expressed about migrants flocking to Northern Ireland to avoid deportation to Rwanda – there is absolutely no benefit whatsoever of doing so. We’re operationalising this policy on a Naba (Nationality and Borders Act) basis.”

The Illegal Migration Act provides new powers for the Government to detain and remove asylum seekers it deems to have arrived illegally in the UK. Central to the new laws is the scheme to send asylum seekers to Rwanda.

Mr Justice Humphreys delivered judgment at Belfast High Court on Monday in two challenges against the Act that focused on the peace process human rights protections guaranteed by the Windsor Framework.

The judge found that several elements of the Act did cause a “significant” diminution of the rights enjoyed by asylum seekers residing in Northern Ireland under the terms of the Good Friday Agreement.