Mr Hague has warned that it can poison the party from the inside. He was the Tory leader in 1998 and laid down a policy that the Conservatives would oppose Britain joining the Euro. There were calls within his own party to deselect the rebels that opposed this key Conservative policy, just as Theresa May faces similar contemporary calls.
There have been suggestions that Nick Boles, Tory MP for Grantham and Stamford, might face deselection.
Mr Hague warned in the Daily Telegraph today of the dangers of enacting these purges, saying “of those who from time to time disagree with the leader, or indeed the activists”.
He has highlighted the expulsion of differing voices within the Labour party as an example of the ‘poison’ that this approach can generate.
The former Leader of the Opposition said: “Attempts to deny the party nomination to MPs who take a different view from the majority or the leadership are another matter, and can poison a party from the inside.
“You can see this very clearly from current events in Labour, where the approach of possible reselection meetings this year is contributing to the growing speculation about a new splinter party.”
He cites the campaign against Luciana Berger, the MP for Liverpool Wavertree as an example of dangerous party purges.
Referring to Mrs Berger’s treatment, Mr Hague said: “She is in Labour’s moderate tradition and probably because she has repeatedly raised concerns about anti-Semitism in the party.
“She has needed police protection at Labour conference.
“Yet instead of backing her up, Jeremy Corbyn’s acolytes are undermining her, as the recent harsh words about her from John McDonnell have shown.”
Although Mr Hague does explain that MPs should not have complete freedom of opinion.
He said: “If they vote against their party on a vote of confidence, that is the same as quitting the party, and should be treated as such.
“And if they are not applying themselves to serving their constituents, their local party should hold them to account.”