THE Greens leader, Bob Brown, is to increase pressure on the government to strengthen its mining tax just days before his party assumes control of the Senate, which will give it the final say on the shape of the policy.

In a speech to the National Press Club today, Senator Brown will cite research the Greens commissioned which shows that in the next five years $50 billion in profits from Australian minerals will be sent overseas in dividends to foreign owners.

Amendments ... Greens leader Bob Brown wants a stronger carbon tax. Credit:Alex Ellinghausen

He will argue that Australian mining companies are 83 per cent foreign-owned and that more of the bounty needs to be kept in Australia to seed a sovereign wealth fund and provide assistance to those sectors of the economy suffering because of the mining boom.

''Amid a mining boom, while the government faces budget pressures and as the Reserve Bank of Australia prepares to raise interest rates, parts of the economy are wallowing,'' he will say.