The Liverpool Echo has an interesting article on its website – see link below:-
One of the major reasons Merseytram was killed off was because the first line proposed to be constructed was NOT to John Lennon Airport. Those that followed the Merseytram saga/fiasco will recall that Merseytravel, in trying to chase government grants/support, decided the first line was going to be built to Kirkby. And this despite it being a community which already had and still has a Merseyrail heavy rail station and a 15 minute frequency train service. It was a mistake from which Merseytram never recovered.
Since then there have been a number of calls for Liverpool’s Airport to be connected by rail despite air travel being an environmental challenge (to put it politely) as we dive head-long into an climate crisis which the world is struggling to address in any meaningful way.
You could say that a rail connection to John Lennon Airport (light or heavy) has been on the agenda for many years but so far the powers that be have failed to find an answer and when they got close (via Merseytram) it got shunted into a siding.