Imposing pet passports for dogs, cats and ferrets to travel from one part of the UK to another has been branded an “outrage” at Westminster.

The condemnation came as the House of Lords debated regulations paving the way for a scheme which would require animal lovers on the British mainland to have documentation in order to visit Northern Ireland.

Critics view the move as further evidence of Northern Ireland still having to follow EU rules post-Brexit and being treated differently from the rest of the UK – a major source of contention to the unionist community.

The paperwork, which will be free to apply for, includes a declaration that the owner will not travel onwards to Ireland or another EU country with their pet or assistance dog.

Animals will have to be microchipped and have their own individual pet travel document, which will be valid for its lifetime.

Northern Ireland residents returning after a stay in Great Britain with their pet or assistance dog will not need a travel document.

The scheme is being introduced under the Windsor Framework, a revised deal for Northern Ireland’s post-Brexit trading arrangements aimed at tackling issues caused by the protocol.

Raising her concerns in Parliament, Baroness Hoey, a Northern Irish Brexit supporter and former Labour MP, said: “These regulations are in effect about a new aspect of the Irish Sea border that has not had expression until this point because of the grace periods.”

She added: “The experience of visiting Northern Ireland with your pet dog or cat, or even a ferret, will be made to feel like a visit to a foreign country.

Lady Hoey went on: “This could spell the end of holiday trips for pet owners from GB to NI and then on to the Republic, when they want to explore both Northern Ireland and the Republic.

“If they have a pet passport, they will have renounced their right to go to the Republic. That makes the border more of an obstruction than having border control posts on it, because at least in that eventuality, you could still cross over it.”

Rejecting claims it was a result of the UK leaving the EU, she said: “The reality is that this is happening precisely because Northern Ireland has not got Brexit.

“As we say repeatedly, it is still subject to EU rules and the EU could change the rules overnight.”

Former DUP deputy leader Lord Dodds of Duncairn said: “Every one of the statutory instruments that come forward under the Windsor Framework must be properly debated, because these laws are being brought forward to implement what a foreign jurisdiction has decided should be the law of the United Kingdom.

“In the 21st century, we should not accept colonial rule. We abolished it elsewhere. We believe it should not be tolerated for one second. People should have the democratic right to decide their laws for themselves, in their interests.”

He added: “The ridiculous part about this debate is that we are having to debate European laws regulating the movement of pet animals owned by British citizens between one part of the United Kingdom and another. That is an outrage.”

Lord Dodds went on: “As I said, there will be hundreds, thousands more of these regulations, in all areas, affecting the daily lives of people in Northern Ireland. They all add up to a grievous assault on Northern Ireland’s constitutional position.”

But former leader of the Social Democratic and Labour Party (SDLP) Baroness Ritchie of Downpatrick said: “I support the Windsor Framework because it is a necessary legal device to deal with the complexities that were presented to us in Ireland, north and south, on the issue of Brexit.

“We need a pragmatic solution rather than choosing to have political contests and duels simply for the sake of them.”

Introducing the regulations, environment minister Baroness Hayman of Ulloch said: “This scheme will simplify the requirements associated with moving pet dogs, cats and ferrets from Great Britain to Northern Ireland significantly.

“It replaces single-use animal health certificates with a free-of-charge lifelong travel document and removes the need for costly pet health treatments.

“Pet owners who travel frequently with their pets, or those who rely on the services of an assistance dog to travel independently, will benefit substantially from this change in approach.”

However, she acknowledged the concerns raised by peers and promised to continue engagement with them.