I think your title is hugely MIS-LEADING.

It's not expansion as people would understand the word to mean but rather the proposed "flying longer hours during the day and also Saturday afternoon and evening". Use of correct language is important so people can quickly relate to what you ae attempting to communicate, their is nothing worse than mis-communication i.e. saying one thing when you actually mean something else, which in effect is what you appear to you have done.

And as you further say "not permitted ever since they opened", so hopefully as it was not originally permitted, it may not be permitted now.

So, perhaps change the title of the thread to ", Proposed extended flying times at London City Airport" which much more represents what they are attempting to do.