If the UK government did not follow through with Brexit what would happen?
The United Kingdom European Union membership referendum (23rd June 2016) resulted in a vote in favour of the UK leaving the European Union.
To give effect to the referendum result, i.e. to leave the EU, Parliament needs to notify the EU that it is enacting Article 50 of the Treaty on European Union.
If Parliament did not follow through on the referendum result and trigger Article 50 to begin the process of leaving the EU what would/could happen?
Traditionally the UK holds that Parliament is sovereign. Some modifications to the absolute sovereignty of Parliament have been made, starting with the Parliament Act of 1911 and including aspects of human rights law (contrary to popular belief withdrawal from the EU will not in itself change the legal situation regarding human rights), but it is basically still in place. Therefore in law Parliament does not have to answer to anyone, and the referendum is only advisory.
But to disregard the majority result of a hard-fought referendum that was presented to the British people by politicians from all major parties and from both the Remain and Leave sides as the most important democratic vote in their lifetimes would be political suicide. The legitimacy of any government that tried it would be fatally undermined, and not only among those who voted Leave.