This section applies where a person who disposes of land ("the old land") to an authority exercising or having compulsory powers declares, in his return for the chargeable period in which the disposal takes place—
that the whole or any specified part of the consideration for the disposal will be applied in the acquisition of other land ("the new land");
that the acquisition will take place as mentioned in subsection (3) of section 152; and
that the new land will not be land excluded from section 247(1)(c) by section 248.
Until the declaration ceases to have effect, section 247 shall apply as if the acquisition had taken place and the person had made a claim under that section.
For the purposes of this section, subsections (3) to (5) of section 153A shall apply as if the reference to section 152 or 153 were a reference to section 247 and the reference to the old assets were a reference to the old land.
In this section "land" and "authority exercising or having compulsory powers" have the same meaning as in section 247.