Government asked Prince for approval because the changes would have affected his income

Prince Charles was asked to approve UK planning laws because they might have an effect on his own estates and income, documents obtained by the Guardian reveal.

In 2008 Baroness Andrews, a Labour minister for the department for communities and local government at the time,wrote to the Prince’s private secretary asking his consent for changes that would “affect the interests of the Prince of Wales”.

The draft bill proposed to change laws about handling disputes and payments in building contracts.

Clarence House said the practice of seeking the Prince’s consent for such bills was a “longstanding convention” and not about seeking the Prince’s view. The department for communities and local government said that no changes had been requested by the Prince and therefore none were made.

Last year Prince Charles received £18m in profit from his estates to fund his lifestyle and work.