The problem with a GE is this.
There is a majority now against Brexit. A binary referendum will show that we no longer want Brexit.
A GE is FPTP and non-binary. The pro-Brexit minority is concentrated in the Tories and BP. The anti-Brexit majority is spread over far more parties. The Tories may get only 35% support but will win a majority in Parliament.
Only a referendum reflects what the electorate thinks of Brexit.
We had a referendum
The result hasn't been enacted
Parliament has reneged on it's duty to the electorate
A GE will settle matters
People vs Parliament.
The referendum was not legally binding. Thereís no one source that can prove this statement true. That follows from the fact that the European Union Referendum Act 2015 didnít say anything about implementing the result of the vote. It just provided that there should be one.
In other countries, referendums are often legally bindingófor example, because the vote is on whether to amend the constitution. The UK, famously, doesnít have a codified constitution.
A UK referendum will only have the force of law if the Act setting it up says so. In practical terms this would mean someone would be able to go to court to make the government implement the result.
So, purely as a matter of law, neither the government nor Parliament has to do anything about the referendum.