The UK’s global reputation is at stake if it breaks its Brexit promises to the EU, the European Parliament warned.

Measures to avoid a hard border on the island of Ireland, including “alignment” with the bloc’s rules over Northern Ireland-related issues, were agreed shortly before Christmas.

Irish MEP and the vice-president of the European Parliament Mairead McGuinness promised that accord will be put into law.

She said: “The EU regards that text as real, as an agreement, it is not a fudge and it will be put into law.

“The UK as a global player and a major country will be mindful of the fact that if it reneges on an agreement with its EU partners at the moment the world is watching, every single country around the globe is watching, and if it misbehaves on this, note will be taken.

“Who will do a deal with a country whose word cannot be taken as truth?”

Three scenarios were proposed in the text of an agreement between the EU and UK published in December.

It initially envisages dealing with issues such as protecting trade across Northern Ireland’s invisible land border with the Republic as part of the overall relationship between member states and Britain.

If that fails, the text said the UK would propose specific solutions addressing the “unique” circumstances of the island of Ireland.

Only if that is also rejected will the United Kingdom “maintain full alignment with those rules of the Internal Market and the Customs Union which, now or in the future, support North-South co-operation, the all-island economy and the protection of the 1998 Agreement”.

The 1998 Good Friday Agreement largely ended decades of violence and enshrined many of the North-South co-operation measures in an international treaty between Ireland and the UK.

Ms McGuinness is part of Ireland’s governing Fine Gael party.

The Oireachtas European Union Affairs Committee of public representatives in Dublin heard from Ireland and Northern Ireland MEPs about preparations for Brexit.

Sinn Fein MEP Martina Anderson said the Irish Government needed to ensure the entitlements of the people of Northern Ireland were upheld.

“It is the Irish Government that needs to ensure that we stand over the rights.”

She said there was already a border in the Irish Sea preventing animal disease from spreading between countries and the infrastructure was already in place.

She added she was not calling for any hard borders, particularly not one in Ireland.