I just had a look at the Reclaim Labour website (reclaimlabour.blogspot.com) which has the aim of taking the Labour Party back for the Left from the New Labour careerists.
The list of policy criticisms - privatisation of public services, Iraq and the American alliance, top-up fees, workers' rights, Trident and civil liberties - are familiar and ones where I broadly agree with Reclaim Labour.
What I don't think is helpful is criticising people who support New Labour as 'careerists'. I've wanted Tony Blair to resign as leader since 1998 and campaigned against a whole range of New Labour policies, but even I can see that there are a whole range of reasons why people support Tony Blair and New Labour which have nothing to do with advancing their careers. There are millions of people who voted for a New Labour government in 2005, and thousands who were actively campaigning for its success, and realistically if there is to be a left wing Labour government, we will need to win over the vast majority of those people.
There are always a few people who are involved in politics for what they can get out of it, though I wouldn't worry because they are currently flocking to 'Project Cameron'. But to be honest, the main thing which determines whether people are on the left or the right of the Labour Party was identified by John O'Farrell, who found himself on the soft left because the soft left people were fun to spend time with, unlike the humourless hard lefties or the pompous right-wing councillors. In some places the local party is dominated by friendly lefties who go out of their way to welcome and involve new people, in others the local activists who do a lot of work in the local community and get new people involved are all staunch loyalists. In either case, the discussions and arguments that people hear when they are first getting involved in politics tend to stick with them, and the way to get more supporters is by being welcoming to new people, not by slagging off people who disagree on particular policies.
Since it is mostly a matter of accident and local culture about whether people end up on the 'left' or the 'right' of the Party, it is deeply counterproductive to make personalised attacks which assume the worst about people's motivations. Calling off the search for 'traitors' or 'careerists', and putting that time to persuading people to support our aims and our ideas for how to achieve those, is the key to getting a left wing Labour government.