Editorial: The UK needs to set out its plan for retaliation against Ireland for its outrageous legacy legal action against Britain

Rishi Sunak has said an unusual thing for a UK prime minister when he cited Ireland ​in a criticism.

​The prime minister said yesterday: “We're not going to accept returns from the EU via Ireland when the EU doesn't accept returns back to France where illegal migrants are coming from. Of course we're not going to do that.”

It is not unusual for Tory prime ministers to criticise the EU, but highly unusual to criticise Ireland. There is institutional weakness in London, in both main parties, in the face of Irish politicians who routinely and openly criticise the UK.

For much of the last year this government has been cool towards Ireland, which is both welcome and overdue. Even so, it is a surprise to hear Mr Sunak say so emphatically that he will not accept Irish returns. It is essential that this line is maintained, and that the solution to immigrants travelling to Ireland via Northern Ireland does not become checks on Irish Sea movements.

Meanwhile, it is still unclear what – if anything – London plans to do in retaliation for Ireland’s outrageous legacy action against the UK. That legal case was almost encouraged by Michael Gove last year when he foolishly said an Irish action would not damage relations.

The very least London could have done was to decrease the frequency of British Irish Intergovernmental Conferences, one of which happened yesterday and has mysteriously become a four-times-a-year event.

Yesterday, Chris Heaton-Harris said “our relationship is strong enough to deal with” the Irish action . While the junior NIO minister Lord Caine called the case “unnecessary” such soft criticism is a wholly inadequate response to being sued by a state that has given a flagrant de facto amnesty to IRA terrorists since 1998, and has had no spotlight on its facilitation of such terrorists in the three decades prior to that by refusing to extradite them.