Boris Johnson’s proposal to solve the Irish border question with a single regulatory regime north and south of the border for food and agriculture will never be enough to replace the backstop, Ireland has said.

The country’s deputy prime minister, Simon Coveney, said Ireland will give a “generous” response to the proposal but dampened hopes that it amounted to a major breakthrough after a 90-minute meeting with Michael Gove in Cambridge on Friday night.

“I wouldn’t like to pretend that if we can solve the agri-food issue, then technology can solve the rest,” Coveney told a meeting of the British Irish Association also attended by Gove, the minister in charge of no-deal Brexit planning.

The idea of an epidemiological zone covering the whole island had been mooted previously in early Brexit talks but ultimately rejected because of the implacable opposition of the Democratic Unionist party, who said it would amount to checks down the Irish sea.

However, Johnson revealed the shift in policy on Tuesday and sources have confirmed it is a “serious proposal” which will be put to the taoiseach, Leo Varadkar, when the two premiers meet in Dublin on Monday.

There was some scepticism that what the British prime minister had in mind was regulatory alignment on food between Ireland and the UK, something suggested by the Alternative Arrangements Commission, the privately funded body which has been examining how to replace the backstop.

But sources have confirmed that this is not the case and Johnson’s thinking is that Northern Ireland would remain aligned to EU standards in the Republic of Ireland if the UK diverged from EU standards at a future point.

Asked if there was merit in this proposal, Coveney said “yes” and added that he had a “good conversation” with Gove during his meeting.

But Coveney warned that Ireland found Johnson’s decision to backslide on commitments to Ireland in his letter last month to the president of the European council Donald Tusk a major problem that was unlikely to be resolved in the six weeks to Brexit day.

“The letter from PM Johnson to Donald Tusk, and the element of that letter which no longer committed to the commitments made in December 2017 [in the joint report ending the first phase of Brexit talks], that [said] the fallback was regulatory alignment if all else fails – for us that was really concerning, significantly denting trust between the two governments.

“If there is emerging thinking within the British government moving back towards regulatory alignment, rather than trusted trader schemes, scanners etc, then that is progress,” he said.