That being said, apparently the UK government did consider swapping in the late (swinging) 60s but eventually decided against it. This was probably considered following Sweden's own change in 1967.
There would be if they built a road tunnel.
The Channel Tunnel (French: Tunnel sous la Manche), sometimes referred to informally as the Chunnel,[3][4] is a 50.46-kilometre (31.35 mi) undersea railway tunnel, opened in 1994, that connects Folkestone (Kent, England) with Coquelles (Pas-de-Calais, France) beneath the English Channel at the Strait of Dover. It is the only fixed link between the island of Great Britain and the European mainland. At its lowest point, it is 75 metres (246 ft) below the sea bed and 115 metres (377 ft) below sea level.[5][6][7] At 37.9 kilometres (23.5 mi), it has the longest underwater section of any tunnel in the world and is the third-longest railway tunnel in the world. The speed limit for trains through the tunnel is 160 kilometres per hour (99 mph).[8] The tunnel is owned and operated by Getlink, formerly Groupe Eurotunnel.
https://delta.tudelft.nl/en/article/damming-north-sea-good-i...
My question wasn't whether the UK would ever do it (now) but whether they did or should have considered it in the early 60s.
Not sure what I feel about the speed limits. Being part metric and part imperial seems like the worst of both worlds tbh. The pint is fine. You aren't going to do a lot of math with the pint. Worst case you'll wonder how many pints to a 50L keg). But mph is just terrible. I mean just do km/h when everything else is metric in terms of distance! Also, do L/100km not mpg (or km/L). The volume-per-distance is the one that composes mathematically e.g. in averages.