In all likelihood, yes: they are from a faction of the Labour party that was routinely surveilled by police throughout the 20th century (and more recently, in all likelihood).
The election manifesto for Labour in 1983 contained pledges to abolish the secret services, too.
Not to mention the fact that this same part of the Labour party is often engaged in protests that will have left wingers as attendees and speakers. They're very often on the sharp end of both surveillance and crackdowns on protest.
That combined with their belief that the police are racist (eg the Met) and that prison is generally harmful is not likely to produce an authoritarian programme.
They'd have dealt with large scale tax dodgers too, unlike the current leadership.
He has publicly clashed with the powers that be about increasing police powers.
But I don’t have a clear answer for your question, especially as he has many supporters who might not vote along his own lines.
https://www.bbc.com/news/election-2017-40154361