Opponents of Angela Merkel are using the type of tactics that led to the rise of British Labour's Jeremy Corbyn to try to stop her forming a new government in Germany.
A rebel movement is urging thousands of people to become members of the centre-left Social Democrat Party (SPD) inorder to block it joining a new coalition under Merkel.
The initiative is being spearheaded by the SPD's youth wing, the Jusos, which narrowly failed to stop the party entering formal coalition negotiations in a vote at the weekend.
A final deal still has to be approved by a full vote of the membership, and the Jusos activists believe they can recruit enough members to block it.
"For the next step, we need you NOW," Kevin Kuhnert, the Jusos' 28-year-old leader, tweeted alongside a link to apply for SPD membership.
"Now it's important to get as many coalition critics into the party as possible, so we can overturn the result in the membership vote," Frederick Cordes, a regional Jusos leader, said.
Angela Merkel. Photo / AP
"We're planning a national campaign under the slogan, 'a tenner against the coalition'." The slogan refers to the cost of two months' party membership. The monthly fees are only €5 ($8.40) for those earning up to €12,000 a year — which includes many of the Jusos' target demographic of students and young people.
The idea — reminiscent of Momentum's efforts to pack the Labour Party with Corbyn supporters — is also backed by a left-wing faction within the SPD, the Democratic Left Forum 21, who have come up with their own slogan: "Come in, say No!"
The SPD said there had been hundreds of new membership applications since the weekend vote in favour of coalition talks.
However, the Jusos and its allies have a major task before them. The party has 440,000 members, and it says it will set a membership deadline for anyone who wants to vote.
Delegates at a special party congress narrowly voted in favour of formal coalition talks at the weekend, with just 56 per cent in favour. Most commentators believe the current membership is more likely to support a coalition than the highly politicised delegates, though there is no reliable polling data.
The narrow vote in favour of negotiations left the position of Martin Schulz, the SPD leader, severely weakened, with many questioning his future. His performance at Sunday's congress was generally considered to be lacklustre.
