BP has come under fire to suspend shareholder dividends from two US senators until the Gulf of Mexico clean up costs have been calculated.

In an open letter from the office of New York senator Chuck Schumer and fellow senator Ron Wyden, the senators attack moves by BP’s chief executive to reassure shareholders that the company will pay its dividend as planned.

In a joint statement, the senators say, ‘We find it unfathomable that BP would pay out a dividend to shareholders before the total cost of BP’s oil spill clean-up is estimated

‘While we understand the need to reassure shareholders that the disaster in the Gulf will not substantially impact BP’s long term financial health, we are concerned that such action to move money off of the company’s books and into investors pockets will make it much more difficult to repay the U.S. government and communities that are working around the clock to stem the damage caused by this devastating oil spill.’

BP has continued to reassure investors that it will maintain its £6.8 billion (US $10 billion) annual dividend, but the company has now lost over 36 per cent of its market value since news of the Gulf of Mexico disaster broke.

Since the Obama administration insisted BP absorbs the full cost of the clean-up, and BP has agreed to do so, senators Schumer and Wyden claim the company should maintain high capital reserves to ensure it has the resources to deal with this worst-case scenario.