Details of the measure could be set out in legislation resulting from this week's European summit in Amsterdam. The treaty signed at the conference said that future elections in Europe would be held "in accordance with principles common to all member states".
Although the Foreign Secretary, Robin Cook, said before the general election that he expected the 1999 elections to be held under PR, more recently he had appeared to hint that the timetable might be too tight to do that. The decision to go ahead will be welcomed by the Liberal Democrats, who struck a deal on the issue with Labour in March, and also by many Labour MPs who are pro-PR.
Tony Blair has said in the past that he is not persuaded of the arguments for any such change to Parliament, though a referendum has been promised.
The most likely form of PR for the Euro-elections will be a regional list system, under which the country would be split into groups of constituencies. Each party would then put up a list of candidates from which voters could choose, picking some from each party if they wished.
Another imminent announcement is the appointment of an Electoral Commission to look at the whole issue of PR, and it is possible that the decision on the 1999 elections will be confirmed at the same time.
One of the reasons why Labour may be keen to push through the measure is thought to be political rather than philosophical. Party sources fear that by 1999 their popularity may have waned somewhat, and that they could stand to lose some seats at the European elections. A new voting system would muddy the waters and make it easy for the Government to talk down the problem.
A spokesman for the Liberal Democrats welcomed the news that the measure, agreed as part of a constitutional package drawn up by the two parties before the general election.
"PR is the only way that every person in Britain will get a vote which counts. All the talk of tactical voting which happened at the last election will disappear if everyone gets a vote which they can cast for the person they want to get elected," he said.
The Amsterdam treaty is significant because it added new flexibility to an earlier commitment to hold European elections under a "uniform procedure."Reuse content