CANBERRA - Australian Trade Minister Mark Vaile has been elected Deputy Prime Minister as the embattled Labor opposition prepares to unveil a new front bench on Friday to face the most powerful Australian government in 25 years.

Prime Minister John Howard's conservative government will have control of the upper house Senate when parliament returns in August after a six-week winter break, with new senators elected at last October's poll taking up their positions.

This will allow the government, re-elected for a fourth straight term, to pass unamended contentious legislation such as a planned A$30 billion-plus ($23 billion-plus) sale of its majority stake in telecommunications giant Telstra Corp. Ltd.

Howard will take a new-look ministry into the next parliamentary session when Vaile replaces John Anderson, who is standing aside for health reasons, as deputy leader to face a center-left opposition Labor party in apparent disarray.

Transport minister Anderson's departure will force a reshuffle of Howard's ministry, but Vaile said he hopes to retain the trade portfolio.

Vaile, 49, has a strong international profile and negotiated Australia's free trade agreement with the United States.

"I have a good working relationship and a high level of trust, respect and understanding with the prime minister," Vaile said late on Thursday after he was elected leader of the National party, the junior partner in Howard's Liberal/National coalition.

The National party leader is traditionally appointed deputy prime minister under arrangements with Howard's Liberal Party.

"I believe the (National) party needs a leader who is certain to have the energy to meet the challenges this will bring and to take the party forward to the next election," Anderson said in announcing his resignation, which takes effect in mid-July.

Agriculture Minister Warren Truss replaces Vaile as deputy leader of the Nationals.

Labor, which has continued to struggle in opinion polls since its crushing election defeat in October, plans to unveil a new front bench later on Friday that leader Kim Beazley said was needed to hold the "arrogant" government accountable.

Australia's next national election is due in 2007.

($1=A$1.28)