BBC Ceefax
" The Policy Exchange suggests 40% of the trade union members in a workforce should be required to vote for a strike for it to be valid."
The TUC claimed it was " a crude attack on workplace rights."
What is not explained is what represents a workforce, but I would think it relates solely to the section in dispute; eg BA cabin crew and BASSA.
A simple majority when electing MPs is deemed acceptable ( for the time being ), but in industrial disputes it's wide open to abuse particularly when ex-union members are still receiving documents from Unite/Bassa.