GERMANY’S Social Democrats (SDP) are taking a leaf out of the New Labour handbook in a bid to stop new members blocking a coalition deal with Angela Merkel’s Christian Democrats (CDU).

Party officials plan to introduce a cut-off point after which new members will be ineligible to take part in a ballot on coalition terms. They said they would decide on a date next week.

Similar administrative tricks were used by the Labour Party bureaucracy in the 2015 and 2016 leadership elections in a futile bid to stop socialist candidate Jeremy Corbyn from winning.

Social Democrat leader Martin Schulz won permission to open negotiations with the CDU and its Bavarian sister party the Christian Social Union at the weekend, but the terms of a final agreement would go to a ballot of the membership.

Many are sceptical of another “grand coalition” with the right after last September’s disastrous general election, which saw the SDP drop to just 20 per cent of the vote, its lowest share since the second world war.

The CDU also lost seats in a poll which saw modest gains for The Left party and the Greens and huge advances for the neoliberal Free Democrats and far-right Alternative for Germany, which won 80 and 94 parliamentary seats respectively, both up from zero at the previous election.

The SDP youth wing, the Young Socialists, launched a campaign offering two months membership for €10 (£8.70), urging people to join up and vote against another coalition.

But SDP deputy leader Thorsten Schaefer-Guembel said: “A short-term membership with the goal of influencing our vote is contrary to our principles.”