BORIS Johnson has been told “English nationalism” never ends well as he came under attack for preparing to abandon the Brexit withdrawal agreement he signed with the EU last year.

Neale Richmond, a senior Irish politician, warned the Prime Minister’s proposal to override key parts of the treaty would put the Northern Ireland peace process at risk.

“This is a reckless decision that not only puts the border in Northern Ireland at risk by once again opening the door to border checks or a potential hardening of the border; but indeed, puts peace on the island of Ireland at risk also,” writes Richmond in The National today.

“To think that the British Government is prepared to shirk its responsibilities to not one but two international agreements to sate domestic political concerns in England is very worrying.

“What would potential partners think of the UK when it seems so willing to turn its back on agreements, particularly ones which have peace at the heart of them?”

He added: “Brexit will have a huge impact on all four nations of the UK, and yet the discourse and negotiation has largely been driven by England. By the British Government not involving the nations more directly in the Brexit process, they have put confidence in the Government at risk, especially in Scotland and in Northern Ireland.

“The longer-term consequences of leaving the nations out of this discourse is not yet known but English nationalism rarely ends well.”

Richmond, whose article appeared on the website for the pro-European group, eu+me, hit out as Northern Ireland’s pro-Remain parties warned overriding elements of the Brexit withdrawal deal would amount to a serious betrayal of an international treaty,

Sinn Fein, the SDLP, Alliance Party and Green Party NI voiced concern at the prospect of the UK government introducing domestic legislation to supersede parts of the deal’s Northern Ireland protocol governing state aid and customs arrangements.

In response to a Financial Times report outlining Johnson’s intention, the parties have written a joint letter to the Government and the EU demanding that the terms of the treaty are honoured.

Under the protocol in the deal, Northern Ireland will continue to follow single market rules for goods and administer the EU’s customs code at its ports.

It was designed to avoid a hard border, but Unionists have been opposed to it, insisting it creates an economic border between the region and the rest of the UK.