English power comment

Stephen Calder Unless there's no overall majority, in which case, as in 1910, 1922, February 1974, 1976 and 2017, the Government tends to turn first to (since 1922, Northern) Ireland, before exploring other arrangements (e.g. Great Britain wide parties, followed by the Welsh then Scottish nationalists, if not sufficient). 

For purely English matters there's now to slavery beneficiary David Cameron (his surname being the limit of his Scottishness)'s answer to fellow and far far more aristocratic Etonian (but unlike Cameron Labour not Conservative) MP (Scottish Earl) Tam Dalyell's West Lothian question, with the speaker being able to rule on any disputes. 

It's telling that, rather than offering devo-Max and an actual veto on leaving the EU as a result of a referendum he had promised to put in the Tory manifesto in his 2013 speech to the Bloomberg finance and media empire, his immediate response to Scotland's narrow 2014 vote to Remain in the UK, was to provide his characteristically shallow, incomplete, shallow, back of a fag packet instantaneous answer to the West Lothian question.

His West Lothian response doesn't answer the Greater London Authority question. This is a devolved area (Transport, police, health planning, education, etc) and yet its MPs can vote on those matters for the rest of England. Nor the Hertfordshire transport question, as the Metropolitan underground line has stations and termini in Hertfordshire but no representation as of right for their representatives on relevant transport bodies. 

With more and more elected mayors and devolution below national levels, this is ever more a problem. It should be noted that Cornwall was incorporated by force into Wessex, the Kingdom of the West Saxons and predecessor state to the Kingdom of England (first crowned King, Edgar, was in 973(as was the Jutish Isle of Wight, from where I have ancestry (as well as from pretty much all over the British and Irish Isles and Brittany, Normandy, Denmark, Hungary and even from King David via Jewish Roman senators, inter alia). The Cornish and Isle of Wight questions need to be answered (including building proposed tunnels and bridges to the Isle and devolution leading to eventual independence within the EU and comprehensive Cornish-English bilingualism, if the Cornish nation wants it).

The situation of England has parallels to that of Russia prior to the establishment of a Russian Soviet Federated Republic, rather late on in the history of the Soviet Union, except that the English resident and identifying proportions of the population, at over 80% of the UK population has always been far more preponderant.

It would seem likely that the UK Parliament will eventually become the rump English Parliament as everyone leaves. Over 25% of Londoners want their own state according to some poles. Already because of the expansion of London County Council into Greater London it has incorporated all of Middlesex (whose capital was Uxbridge, Johnson's last constituency), and parts of the surrounding counties and fellow ancient Kingdoms of Kent, Essex, Hertfordshire, and Surrey into itself, transferred to its Greater London successor. Surrey County Council continues to meet in its ancient capital of the Royal Borough of Kingston-upon-Thames, outdoor coronation place of the King's Stone (still embedded literally in the street just before the entrance to a church yard leading to a church used for part of the ceremony) of Bretwaldas and later Kings of England until Harold II Godwineson was crowned (with the unanimous support of the Witangemot, upon the recommendation of his predecessor) on January 6th 1066.

The Greater London area was last an independent state under the Romano-Britons after the withdrawal of the Roman legions in AD410, prior to its conquest by the invading Angles over a century later. It could be so again, rejoining the EU and possibly expanding to include neighbouring pro-Rejoin Counties, if the UK or England doesn't rejoin as a whole or in whatever parts it has disintegrated into. There are no size limits on self-determination, just a requirement to try to try autonomy within existing boundaries where practicable under the UN Charter.