Munich  - Horst Seehofer, who is expected to be appointed premier of Bavaria on Monday, has promised his party, the Christian Social Union (CSU), he will exert heavy pressure on Chancellor Angela Merkel.

He was speaking Saturday to a party congress in Munich of the Bavaria-only CSU, which elected him party leader. He was the sole candidate. Of the 939 delegates, 786 voted in his favour and 84 against, with the rest not voting or spoiling their ballots.

The CSU was replacing its leadership after a state election debacle last month in which the CSU lost its absolute majority and must enter a coalition.

Delegates blamed the poll loss on Merkel, who leads the CSU's "sister party," the Christian Democratic Union.

Though both parties are broadly conservative, the CDU has rejected a CSU plan to offer a larger tax rebate to commuters, bigger exemptions for heirs from inheritance tax and other tax cuts.

"We, the CSU, are a bundle of muscle," Seehofer, 59, told delegates at the congress, which approved with a huge majority his agreement with the smaller Free Democrat Party (FDP) to rule Bavaria jointly.

"My desk is possibly going to be Munich. But my fighting skills will also extend to Berlin," he said in reference to complaints that the CSU had too little influence within Merkel's three-party coalition.

The other federal coalition partner is the Social Democratic Party (SPD). Seehofer is to give up his post as federal minister of agriculture and consumer affairs.

For the first time in 46 years, the CSU is unable to rule the largely Catholic state of Bavaria without a coalition partner.

Seehofer said his objective as premier replacing Guenther Beckstein would be to restore the CSU's old strength, with 50 to 60 per cent of the popular vote. Four weeks ago the party won just 43 per cent of the votes in Bavaria.

The Bavarian legislature is to meet Monday to elect a new state premier and state government. (dpa)