Corporate calculation

My client is a non-resident corporate body based in the European Union but using my address for UK tax purposes.

It owns commercial property in London and pays tax at 20% on the net rents agreed each year with what is now CAR PT International in Bootle.

There is now a prospect of selling the property which will give rise to an eight-figure taxable gain. Under the relevant treaty this is taxable in the UK as immovable property but the question arises of how the gain and tax liability is to be calculated.

I can find nothing which really covers the point in the authorities I have consulted. All I have found is reference to rents etc. being taxed under income tax rules and the 20% rate is of course the lower income tax rate. There seem to be three possibilities.

First the taxable...