By Steve Kingstone BBC News, Sao Paulo

Mr Cavalcanti says his signature on a key document was forged

One of Brazil's most senior politicians faces possible expulsion from parliament after a formal complaint by lawmakers who accuse him of corruption.

Severino Cavalcanti is accused of demanding kickbacks from a businessman who ran parliamentary restaurants.

Mr Cavalcanti, 74, denies the claim, which is the latest in a stream of corruption allegations in Brazil.

As leader of the lower house of parliament, Mr Cavalcanti is third in line to the presidency.

He is a traditionalist and a champion of parliamentary independence. But now, his colourful career may be cut short.

Lawmakers from five parties have formally called for Mr Cavalcanti's expulsion from parliament.

It is alleged that between 2002-03, he demanded and received $46,000 in kickbacks from a businessman who ran several parliamentary restaurants.

The contract for one particular restaurant was subsequently renewed. Mr Cavalcanti denies receiving bribes. He says his signature on a key document was forged and he points out that all this allegedly happened before he became leader of the house.