Look you can make an argument that slightly more domestic oil production could have happened. But lets actually be realistic. Even best case you don't get that much and it takes a long time.

And its in no way going to solve any of the actual long term energy issues in the UK.

For example, if you assume limited government resources, massive investment in North Sea fossil is just inherently stupid.

Allowing some private exploration and production would be tiny and barley relevant to solve any problem. The right wing people who advocate this as some kind of 'solution' are more delusional then any 'leftist'.