Labour's Maastricht timebomb primed to detonate next week: Anthony Bevins looks at the parliamentary amendment that may yet wreck the treaty

THE CONCEPT of the ticking timebomb, a killer Labour amendment that could be planted at the heart of the Maastricht legislation, was the creation of George Robertson, the Opposition frontbench spokesman on Europe.

As the Independent reported yesterday, the timebomb is now set to detonate next Thursday night, when the Commons and Lords vote on an amazingly bland Government motion on John Major's Social Chapter opt-out, simply noting 'the policy of Her Majesty's Government on the adoption of the Protocol on Social Policy'.

The Labour-inspired timebomb, now Clause 7 of the European Communities (Amendment) Bill, says: 'This Act shall come into force only when each House of Parliament has come to a resolution on a motion tabled by a Minister of the Crown considering the question of adopting the Protocol on Social Policy.'

The explosive content of the clause centres on the relationship between the motion and the resolution. The Commons clerks have advised MPs that the motion can only become a resolution if it is passed.

If the motion is defeated, there is no resolution; if there is no resolution, the Act shall not come into force; if the Act does not come into force, Mr Major cannot ratify the treaty, and is blown up a gum tree.

Before they come to the main motion, however, MPs and peers are expected to be given the chance to vote for a more positive Labour amendment. This will say that the Government should not ratify the Maastricht treaty 'until such time as it has given notification to the European Community that it intends to adopt the Agreement attached to the Protocol on Social Policy'.

Given the complex nature of political forces at work - the Prime Minister and his government; the 40-strong band of Tory rebels; Labour; the Liberal Democrats; Nationalists; and Ulstermen - the next week could yet be one of the most fraught and frenetic since Margaret Thatcher's demise.

With those complexities in mind, Mr Robertson was up until the early hours of yesterday morning working out the possible permutations of what could happen in the Commons next Thursday - and their possible consequences. His scenarios, with implications in his italics are:

'Scenario 1. Labour amendment carried. Amended motion put to the House. Government votes against, along with Tory rebels. Motion lost. Treaty cannot be ratified unless new motion is tabled. Government tables new motion for 27/28 July OR Government accepts decision and refuses to ratify Maastricht.

'Scenario 2. Labour amendment carried. Government abstains on amended motion. Motion carried. Government says it will accept the Social Chapter, OR Government refuses to ratify and treaty falls, OR Government says it has legal authority . . . ratifies the treaty and ignores the vote of the Commons.

'Scenario 3. Labour amendment is lost. Government, with Labour against, but with possible Ulster Unionist, Liberal and even Welsh Nationalist support, will win the main question even if more Tory rebels vote this time. Treaty is ratified.

'Scenario 4. Labour amendment is lost. Main question is lost as Opposition coalition stays firm and more Tory anti-Social Chapter rebels join us. Treaty cannot be ratified because Act cannot come into force. Government comes back the following week with a new motion and wins. Treaty ratified. OR Government comes back the following week with a new motion, the Opposition coalition on our amendment holds and we return to scenarios 1, 2, and 3. OR Government accepts defeat and refuses to ratify. Treaty dead.'