THE ELECTION to a seat in the British Parliament of a jailed IRA terrorist, who is on a hunger strike, is the latest grim development in Northern Ireland. Bobby Sands, 27, serving a 14-year term on a gun conviction, was on the 55th day of his self-imposed fast yesterday in the Maze prison near Belfast, and his condition was such that he could die at any minute. It was presumably to add to the pressure on the British government to save him, by granting his demand for political status for IRA prisoners, that many Catholics in his constituency voted for him. Others no doubt voted for him in support for the IRA.

But what did his election show, aside from its testimony to the compassion of some of Mr. Sands' countrymen and to the cynicism of others? Very little. Who in Britain needs a further reminder that the Catholic minority in the six-British-run provinces of Northern Ireland demands and deserves a different order? Who "needs" a further instance of violence, whether it is directed at Catholics, at members of the Protestant majority or at the representatives of British rule -- or whether it is directed by martyrs at themselves -- in order to understand the imperatives of a political solution?

At the least the government of Margaret Thatcher in London and Charles Haughey in Dublin can fairly be said to be engaged in such a search. Neither Mr. Sands nor his constituents have made a contribution to it. They should have a free member, and a live one, in Parliament to plead their cause.

That does not, however, alter the dire circumstances created by Mr. Sands' strike. His fast has produced sympathetic violence in Northern Ireland, and his death could bring feelings between Catholics and Protestants to an ominous boil. The IRA's actions indicate a judgment that a fresh outbreak of anti-British terror and a civil war in Northern Ireland would be Bobby Sands' appropriate memorials. This puts a heavy burden on the British government to go as far as it can to save the prisoner's life without compromising its own authority or the principle of peaceful change.