Embattled South Australian Premier Mike Rann has lost a key frontbencher, with Bernard Finnigan resigning from Cabinet.

Finnigan, a conservative right-winger and government leader in the Upper House, held the portfolios of industrial relations, state/local government relations and gaming and was acting as the police minister for the travelling Kevin Foley. A short statement from the premier released late this morning said the positions would be reallocated:

Premier Mike Rann today accepted the resignation of Bernard Finnigan from Cabinet and Executive Council.

The portfolios of Industrial Relations and State/Local Government Relations have been allocated to Minister Conlon.

The portfolio of Minister for Gambling has been allocated to Minister Gago.

The Premier does not intend to fill the vacancy created by the resignation.

News Limited website Adelaide Now is reporting Finnigan is the “first casualty” of a disastrous poll published on Tuesday, which had support for the government at its lowest level since 1993. Labor sits at 24% primary vote support, with the Liberals on 50%.

Labor factional leaders are reportedly set to move against Rann and the Treasurer, Foley, within two months, with disgruntled MPs insisting the leadership team is responsible for the poor showing.

But Foley — who has been in the spotlight as a victim of a bar bashing amid accusations his life has become a soap opera damaging the government — has launched a stinging attack on plotting backbenchers, dubbing them “immature political novices”.

“The nervous Nellies and the panickers that are in the Labor Party in South Australia should take a cold shower,” Foley told The Australian. “Aspiring backbenchers who wish to be ministers, and those aspiring to be MPs, have about as much political genius as I do in my left toe.”

Finnigan, elected to the Upper House in 2006 after five years as assistant secretary of the SA branch of the Shop Distributive and Allied (SDA) Employees’ Association, was appointed to the ministry after a reshuffle in February.

On taking his seat in parliament, the Mount Gambier-born 39-year-old declared himself a “servant of Christ and subject of His reign in history” in his maiden speech. Political opponents like the Democrats have attacked his “ardent and overt Catholicism”, which has seen him vote down same-sex rights and speak out against voluntary euthanasia and stem cell research.

Finnigan had joined with other SDA-aligned party conservatives Tom Kenyon, Jack Snelling and Tom Koutsantonis to form a powerful bloc within the Labor caucus. All four won promotions in the February reshuffle.