By Ishbel Matheson BBC East Africa correspondent

Kibaki had promised to fight corruption

Companies in Kenya say corruption is still the biggest obstacle to doing business in the country, according to a new survey involving the World Bank.

When the government of President Mwai Kibaki came to power two years ago it launched an anti-graft crusade.

The country still regularly ranks as one of the most corrupt in the world.

The new report shows that firms pay, or are regularly asked to pay, bribes to judges and officials.

President Kibaki's crackdown on corruption was his flagship policy. It was hugely popular with the public.

Broken promises

Ordinary Kenyans were fed up with having to pay bribes for simple bureaucratic tasks such as the issuing of birth certificates or vehicle licences.

Since then, scandals involving senior government figures have rather taken the gloss off the anti-corruption drive.

But this latest survey by the World Bank and the Kenya Institute for Public Policy Research shows that graft still oils the wheels of business in Kenya.

Half of the firms surveyed said they had been asked for a bribe in the past year.

Many also admitted to paying MPs, senior bureaucrats and judges in order to influence policy or to sway the result of a legal case.

Despite the government's public declarations, the majority of companies also said that gifts or informal payments were expected to secure a government contract.

For anti-corruption campaigners, the report makes depressing reading but its results are not surprising.