Tony Blair has intervened for the first time in the row between government and business over contentious last-minute changes to company law, which will force companies to disclose information on their suppliers and other contracts.

The prime minister came under pressure in the Commons on Wednesday to pledge he would not be swayed by business lobbying into a U-turn over the companies bill when it goes to the Lords next week. Margaret Hodge, the industry minister, provoked a furious business backlash this month by introducing an amendment to the bill requiring directors to reveal relevant information on suppliers.