There's a UK politics tradition called "kicking it into the long grass"
You've got a group of stakeholders who passionately believe X should be done. They've got some strong arguments, and some political backing. You've got another group of stakeholders who strongly think X should not be done. They've got some good arguments, and some powerful supporters.
So how do you resolve the debate? Which of the two groups are you going to upset? It's simple! You just delay the decision. Order a study, set up a committee, change the requirements, whatever. Just hold up any major works for 5 years or so without cancelling the project, and you can leave office making it some other chump's problem.
Nuclear power plant we might need, but it's expensive and nuclear? Long grass. Extra runway at a busy airport, but locals don't like it? Long grass. Decarbonising transport, but it'll raise prices? Long grass. Nuclear weapons renewal? Long grass. Incredibly busy road through a world heritage site? Long grass.