No doubt Dean Mighell’s much reported speech was intended as a tonic for the troops – but it’s demonstrated perfectly how the trade union movement could poison Labor’s chances of victory at this year’s federal poll.

Kevin Rudd acted quickly to forced his resignation from the party – but that’s opened the Labor leader up accusations that he will do anything to get elected.

Mighell has also been described as an “old-style” union boss. There seem to be plenty like him, though.

And given that only 15 per cent of the workforce outside the public sector actually belongs to a union, the entire labour movement could be described as an exercise in nostalgia – a throw back to the good old days. The good old days of TB, unsewered dunnies – and snap strikes. That begs the question of why a political party seeking election in 2007 still holds the bruvvers so close to their bosom.

The Mighell tape certainly blunted Labor’s Question Time attack yesterday. And it also overshadowed Julia Gillard’s address to the National Press Club.

That last part might be the only good thing to have come to Labor from the whole affair, as Gillard backtracked on the abolition of the government’s building industry watchdog, the Australian Building and Construction Commission. That comes on top of other recent reversals over pattern bargaining and allowing unions to charge non-members compulsory bargaining fees.

Labor spinners tell you that standing up to union militancy lets Kevin Rudd look strong.

Instead, Labor’s links to the union movement look more and more of a mistake – and raise the question time and time again of why the shrunken union movement’s influence on a party chasing votes from all sectors of society remains so strong.