Supporters of Jeremy Corbyn are trying to take control of local Labour parties and pass a series of measures against war in Syria and against renewing Trident, a centrist campaigning group has claimed.
In an email sent out by Labour First last week, the group's secretary warned that "hard left" members were trying to force their way into senior positions in local parties.
In it Luke Akehurst alleged that new members were attempting to force MPs to take specific positions on three issues: the renewal of Trident, intervention in Syria, and party membership.
Since Corbyn entered Labour's leadership contest over the summer, there has been a huge spike in membership as hundreds of thousands of people joined the party to vote for him.
Recently, centrist Labour MPs have publicly expressed concern after Corbyn's leadership campaign launched a new campaigning group, Momentum.
Members of Momentum told BuzzFeed News that they planned to take an active role in helping Labour candidates get selected in constituencies but said MPs should not be concerned.
Akehurst claimed however that three motions are being put forward by members across the country.
He said that on Trident, there was a motion looking to send a message from local parties to congratulate Jeremy Corbyn "for declaring that as prime minster he will not authorise the use of nuclear weapons". It also calls for the party to plan for defence diversification "to ensure that reduced spending on armaments will not lead to the loss of jobs".
Corbyn drew a huge amount of criticism from within his own party when, a day after he spoke at the Labour party conference, he said he would never press the nuclear button.
Akehurst said another motion calls for local MPs to "vote against any motion proposed by the government in the House of Commons that seeks support for the bombing of Syria by British armed forces".
And the final motion discusses those who should be eligible for party membership. It puts forward the idea that "there should be no infringement on the rights of free speech and free criticism within the Labour Party". It adds that only people who are known to be racist or abusive, or who actively campaign against Labour candidates in "future elections", should be banned from the party.
A recent poll showed that while Labour members are largely supportive of Corbyn, only 27% of the general public think he should lead Labour into the next general election.
The poll, conducted by YouGov for The Times, will be bad news for Labour MPs who were were hoping to mount a challenge against Corbyn.
Although many have publicly criticised Corbyn's decisions, the poll suggests that due to the continual membership support, Corbyn would win any potential challenge with a comfortable majority.
The party was unable to be reached for comment.