This section applies if—
an interest in land which is a qualifying interest for the purpose of section 33A is acquired by agreement by an authority which has power to acquire the interest compulsorily, and
the interest is acquired from a person who would be entitled to a payment under section 33A, 33B or 33C if the interest is acquired compulsorily.
The authority may make a payment to the person of an amount equal to the amount they would be required to pay if the interest is acquired compulsorily.