Man Ba-bmi
All the posts suggesting that MAN is about to 'throw its toys out of the pram', 'draw up the drawbridge' etc are, although well intended, are pipe-dreams.
Whilst airports are commercial businesses, and on the face of it, free to choose who they trade with, are regulated by international, European and national legislation.
The cornerstone of international aviation is the 1944 Chicago Convention. Article 15 sets out that 'Every airport ... which is open to public use shall be open to uniform conditions'. This Article was intended to allow the development of international aviation, although was amended for US/UK traffic by Bermuda 2.
In Europe, clearly there is EU Restraint of Trade legislation.
In the UK, MAN operates under a CAA Public Use Licence. This requires that 'the aerodrome must be available to all persons (users) permitted to use it on equal terms and conditions.'
In short, as an international airport, MAN would not be able to restrict access to particular carriers. Why would it look to close access to BA/BMI and then see the routes disappear to LPL? More likely, promote through its marketing activity, the alternatives to LHR. And that's what they've started to do, and expect to see more.