Cancellation of TSR-2 was only one of a number of major UK projects cancelled at this time in a misguided attempt to keep the economy from slipping further out of control. There were others such as the Channel Tunnel (yes, it was going ahead at the time though to a smaller scale than what eventually materialised).
Interestingly at Monino Soviet Air Force museum outside Moscow there is a prototype of a very potent-looking
Sukhoi 100 which, just like TSR-2, and at the same time, was cancelled at the prototype stage. There is a sad-looking notice under the nose making the point that "It was NOT cancelled due to any deficiency of the design", obviously put up by someone with project involvement, just like those who defend TSR-2 so vigourously.
The one "high tech" project to escape in the 1960s was Concorde, and this was attributed entirely to MP Tony Benn having a marginal Labour seat at the Concorde factory in Bristol (he'd already lost the seat once and regained it). He was Minister of Technology at the time and key to the decision, and also Minister for saving his own job it seems. The Channel Tunnel was in leafy Conservative Folkestone, TSR-2 was designed in bourgeoise Weybridge (built in Preston I believe but all those I know who were involved were at Weybridge) ..... you get the picture.