Graham Brady has every right to support South East airport expansion or not. It is called free speech and democracy.
You might not agree with him, and that too is called free speech and democracy.
The South East needs another runway somewhere to serve London. London is just not the UK capital. It is a major, highly successful, global city. But rightly, Manchester needs to expand too. I am sure he supports both ambitions.
Manchester, Leeds, Birmingham or Liverpool could never be a replacement or a substitute for London. Those airports will expand serving their local catchments. The money is just not there in the region's at it never will be. That is why most global airlines are not really interested in expanding in the UK outside of London.
It is also the reason, that Thomas Cook Airlines has begun to develop a very successful network of long haul services out of Manchester serving the budget conscious travellers in the North of England and Scotland.