The idea
There should be no Sharia courts, tribunals or Sharia-based judicial proceedings of any kind in any of the UK's legal jurisdictions.
Why is it important?
People who have adopted the UK as their home, regardless of their origin, should be required to abide exclusively by the laws of the UK and not be able to import a legal system of their own. British expatriates in the Middle East are expected to abide by local laws and respect local customs (whether it relates to alcohol consumption or the wearing of revealing clothes in public) and rightly so. It should be no different with immigrants coming to the UK.