The ex-minister, who quit the Cabinet late last year, also claimed the UK’s position on the protocol was being “ignored or misrepresented”.
In those circumstances, Lord Frost said it was “hardly surprising” that the government was considering unilateral action to address issues with the controversial post-Brexit Irish Sea trading arrangements.
Speaking to reporters in Cork on Saturday, Mr Martin claimed the UK had failed to provide clarity to the EU on what it would be prepared to accept to resolve the stand-off on the protocol.
To illustrate his point, he claimed Lord Frost had deliberately raised the issue of European Court of Justice oversight just at the point when European Commission vice president Maros Sefcovic was about to unveil proposals aimed at reducing red tape on trade between Great Britain and Northern Ireland.
Mr Martin made the comments as he responded to questions on the political impasse in Northern Ireland.
In remarks reported by the Irish Times, the taoiseach suggested the fundamental challenge in resolving the protocol issue was not with unionism, but with the approach adopted by the UK government.
“I think unionism has made a case to us and we have discussed it over time with the European Union,” he said.
“The European Union has met the unionist community and it has met with businesses and with industry in Northern Ireland and came forward with proposals.
“But the European Union really has never got a landing zone from the British government in relation to the protocol. It’s very unclear what will suffice for the British government. We have some sense of what would work with unionism, but we don’t have that sense with the British government.”
In an apparent reference to a speech made by Lord Frost in Lisbon last October, Mr Martin added: “Unionism did raise issues about the operation of the protocol which we did work with our European Union colleagues to try and deal with and, if you recall just prior to Maros Sefcovic outlining his proposals, Lord Frost tried to torpedo them by raising the issue of the European Court of Justice.
“That was a deliberate attempt, it seems to me, to undermine what Maros Sefcovic was about.”
In response to Mr Martin’s comments, Lord Frost tweeted: “I wouldn’t normally want to use Twitter to reply to @MichealMartinTD the Taoiseach, but, as he accuses me personally of wrecking the talks last year, I feel I must respond.
“The suggestion the UK has not set out a ‘landing zone’ is simply wrong. Our July 2021 Command Paper and the legal text that followed it were a very clear landing zone, explained in significant detail.
“That July paper was also very clear that the role of the Court of Justice had to be removed. So it is simply wrong to say that I raised it for the first time in October in my Lisbon speech or that the aim was to wreck the talks process.
“If the protocol problem is to be resolved, Ireland & the EU need to engage with what we have actually said.”