4. Nature of the funds on the security of which a local authority may borrow

For the purpose of borrowing money under S. 3 of the Act or guaranteeing interest under S. 5 of the Act, a local authority shall not offer as security any of its funds which is charged under any provision of law for any specific purpose other than the one for which the loan is. proposed to be raised or for which the interest is proposed to be guaranteed, except with the approval of the Government.