Human Rights Act

There will be much more on the plan by the Conservatives to abolish the #HRA if they get re-elected.  But for now, just a single thought.  The whole exercise is predicated on sovereignty.  Allegedly, Strasbourg is preventing our parliament and its MPs from doing what they are elected to do, thus denying it sovereignty.  But the proposal is to abolish the act.  So they can either abolish the act, that is they have sovereignty, or they cannot because the don’t.  It seems they are going to abolish it so they do.  So why do they need to abolish it?  Answers on a postcard please.