12.45 – Attorney-General Nicola Roxon has joined Tertiary Education Minister Chris Evans in departing the Gillard Cabinet.

It is reported that Roxon does not intend to contest the next election.

Reports say Gillard’s reshuffle includes the demotion of Chris Bowen to the portfolios currently held by Evans. Gillard confidante Brendan O’Connor is said to in line for promotion to Immigration Minister.

The reports say Mark Dreyfus will become Attorney-General, whilst Jason Clare is to be promoted.

11.45pm – Later media reports say that Senator Chris Evans is resigning from the Cabinet and the Senate leadership but remaining in Parliament.

Earlier reports left open the possibility that ill health was forcing Evans’s resignation but this now appears not to be the case. A Cabinet resignation ahead of next week’s resumption of Parliament and the first ALP Caucus meeting of the year has quite different implications.

The Sky News correspondent, Peter van Onselen, tweeted this at 11.24pm tonight:

No one should think that Chris Evans will be the only resignation from cabinet in the next 24 hours…I assure you.

— Peter van Onselen (@vanOnselenP) February 1, 2013

Chris Evans, Gillard Cabinet Minister, Government Senate Leader, Resigning

10.00pm – Senator Chris Evans, the Gillard government’s leader in the upper house and Minister for Tertiary Education, is reportedly quitting politics immediately.

Media reports tonight say that Evans will announce his resignation as a minister and senator tomorrow morning. No reason has been given.

Evans has been a senator from Western Australia since 1993. He has been the ALP leader in the Senate since October 2004.

Following the election of the Rudd government in 2007, Evans entered the Cabinet as Minister for Immigration and Citizenship and Government Leader in the Senate.

After the 2010 election, Evans became Minister for Tertiary Education, Skills, Jobs and Workplace Relations. Following a reshuffle in December 2011, he became Minister for Tertiary Education, Skills, Science and Research.

His resignation will require a minor reshuffle. His position as Senate leader will most likely be taken by his current deputy, Stephen Conroy.

A by-election will not be required. Under Section 15 of the Constitution, Evans’s position in the Senate will be filled by the Western Australian parliament which is required to appoint a replacement from the same party.

It has been a lively week for the Gillard government. On Wednesday, Prime Minister Julia Gillard announced September 14 as the election date. Yesterday, the member for Dobell, Craig Thomson, was arrested and charged with fraud.