Kevin Rudd has made a dramatic re-entry into domestic political debate, calling for full democratisation of the Labor Party and lashing the "thuggery" of factional bosses who removed him in 2010.

And his call for reform has been backed by two of the most senior MPs in the Labor Left faction, Anthony Albanese and Mark Butler, with both men urging a greater say for the party rank and file at the expense of factional and union bosses.

Another comeback: Kevin Rudd. Credit:Andrew Meares

Mr Butler also confirmed he would stand for the presidency of the Labor Party when nominations for the position open on March 30, a move Mr Albanese - who is a close ally of the shadow environment spokesman - said had his strong support.

The comments from the three men also represent a direct challenge to Opposition Leader Bill Shorten, who gave a landmark speech last April on the need for party reforms including weakening the influence of unions and extending the direct election of candidates but has had little to say on the subject since then.