Bale was instrumental for Spurs again this afternoon, scoring twice in his side's 2-1 win over Newcastle United to add to his impressive recent goal tally.
"Obviously, we have spoken about that at length and are not going to go through it again," said Villas-Boas.
"Most teams have to hang on to their best players, Barcelona losing Messi would be a disaster, Real Madrid losing Ronaldo would be a disaster so this is exactly the same.
"Teams are dependent on great organisation and also great individuals when they are able to express their football to the maximum. There isn't a release clause in English football, it's very difficult to negotiate with Tottenham as you know and we are not willing to let our best assets go. We can't turn this into a debate every time a player does well"
Bale is currently enjoying his best goalscoring season ever, having found the target 19 times for club and country so far.