The National Executive Committee will outlaw a group of activists in Leeds in the hope of preventing the growth of a nationwide network of anti-Blair dissidents.
The NEC will declare that the Leeds branch of the Independent Labour Network is "ineligible for affiliation to the Labour Party" - the same method used by Neil Kinnock to ban the Trotskyist Militant Tendency in the mid-Eighties. However, the NEC will be told there is growing criticism of the party leadership among the party's grass roots.
Six constituency parties have tabled motions to today's meeting, expressing their hostility to Mr Blair's leadership. Some oppose his move to prevent Ken Livingstone becoming Mayor of London and his attempts to forge closer links with the Liberal Democrats. The Islington South and Finsbury party of Chris Smith, the Secretary of State for Culture, has pleaded with Mr Blair to "lighten up a bit".
Its motion says it is "disappointed at the level of centralised control which the Labour leadership appears to be exercising over the party".
Mr Smith's local party adds: "While we appreciate the need to avoid damaging press stories of splits, we believe there should be more room for constructive dissent than the leadership currently seems prepared to allow."
Labour members in the Tiverton and Honiton constituency express their "growing alarm" at what they call "the manipulation of the democratic procedures" by party officials over the selection of Labour's candidates for the Mayor of London and the leader of the Welsh assembly.
The local party in Folkestone and Hythe criticises the Cabinet for extending policy co-operation with the Liberal Democrats without seeking the NEC's approval. However, the NEC will dismiss the grassroots backlash by acting firmly against the Leeds rebels.
Four left-wingers in the city have already been expelled and two suspended, and today's meeting will approve moves to expel another local activist, Jane Young. In a confidential report to today's meeting, Labour officials say the Independent Labour Network is "operating contrary to the aims and values of the party", has its own finances and is seeking to attract membership.
The report says "it is a cause of considerable concern" that Ms Young is an integral part of the leadership of the independent network. It accuses her of supporting attacks on Fabian Hamilton, the Labour MP for Leeds North East, who was selected to fight the last general election after the Labour leadership vetoed Liz Davies, a former Islington councillor, because of her hard left views. To Mr Blair's embarrassment, Ms Davies was elected to the NEC last September and will be present for today's discussion.
The Leeds group was set up last June, one of the first local branches of a national Independent Labour Network planned by Ken Coates and Hugh Kerr, two members of the European Parliament, who were expelled from the Labour Party a year ago after they decided to join the Green Party.
The Leeds group claims a significant number of Labour members believe Mr Blair is doing to the country what he has done to the party - "essentially, this is to destroy all of the democratic structures in the organisation".
Its campaign material says: "New Labour is no more than an alternative Tory government under a Labour flag."
The group wants to "force the Labour Party back to its principles" and warns: "If this proves impossible, other courses of action may have to be considered."