Two decades after plans were first proposed and with costs overrunning into the billions, Crossrail is finally here – but will the eagerly-awaited purple fleet ever pull into Kent?

Hordes of passengers and transport enthusiasts jumped on board when the first trains along the Elizabeth line departed from London this morning.

It's been billed as the single greatest leap in the history of the capital's tangled pathway of multi-coloured tube trains, and aims to reduce overcrowding, boost capacity and cut journey times.

At precisely 6.30am this morning, "The Purple One" no longer only referred to the nation's favourite Quality Street but a new network connecting far-flung commuters either side of the M25 orbital.

The Elizabeth line stretches from Reading in Berkshire and Heathrow Airport in west London to Abbey Wood in the capital's south-east.

But with the final stop of the £18.9bn rail project shuttling to a stop some six-and-a-half miles from Dartford it bodes the question – will Kent ever feature on the Tube map?

The Prime Minister says "‘we should be getting on" with Crossrail 2, a planned further extension of the network estimated to cost £33bn but this would run between Hertfordshire and Surrey.

It means of the six Home Counties bordering the Big Smoke, Kent is now the only one without a single station jotted on or planned for London's famous Underground.

Early plans for Crossrail 1, which was originally due to open in 2018, had included running the line out towards Gravesend to link up with HS1, the Channel Tunnel rail link.

But this was later axed to save money and a review recommended instead stopping at Abbey Wood.

The Crossrail to Ebbsfleet partnership (C2E) was later set up with the task of supporting an extension to the region amid long term rail issues.

But the campaign – which consists of the councils of Bexley, Dartford, Gravesham and the Ebbsfleet Development Corporation tasked with overseeing Ebbsfleet Garden City – has repeatedly seen efforts scuppered and delayed.

In June 2018, the C2E Partnership secured the backing of the Thames Estuary 2050 Growth Commission which aims to secure future investment in the region.

Then two years later it was given a further boost after nearly £5m was set aside by The Ministry for Housing and Local Government to explore transport options on the corridor between south east London and Ebbsfleet.

The study aimed to understand the development challenges within each area, signpost possible transport improvement options, and identify opportunities for further jobs and housing growth.

Insights were sought from Kent County Council, as well as The Thames Gateway Kent Partnership, and Network Rail.

A public consultation was held on five possible options, later whittled down to three.

They include extending the line, but only as far as Dartford using new dedicated tracks, with extra National Rail services combined with a a new Bus Rapid Transit (BRT) service linking Abbey Wood to Ebbsfleet, and other stations along the North Kent line.

However, the C2E partnership later opted for a more expansive extension.

The preferred scheme would see eight of the 12 Elizabeth Line trains per hour that are currently planned to terminate at Abbey Wood extended eastwards.

This would mean the Elizabeth Line extended from south London to Dartford, Greenhithe and Swanscombe before stopping near to HS1 at Ebbsfleet/Northfleet.

It would share existing North Kent line tracks with the Southeastern and Thameslink network and would see eight trains depart an hour with four destined for Gravesend.

If approved, significant construction works would be required at Dartford station, with some additional sections of track and junction also required along the route.

After several years of consultation a business case signed by all councils in the partnership was sent to the government for consideration.

It was submitted in October alongside a large body of technical evidence to justify the preferred transport options, their development impacts and included a funding and finance strategy.

Gravesham and Dartford council leaders John Burden and Jeremy Kite have both long called for Crossrail to be extended into north Kent.

They have previously said it would be “short-sighted” to ignore its potential given huge developments in the area such as Ebbsfleet Garden City.

Ebbsfleet is the UK’s latest garden city where there are plans to deliver 15,000 new homes and major economic opportunities.

Leader of Gravesham council John Burden (Lab) welcomed calls to extend Crossrail to north Kent and says it will support the government's own levelling-up agenda.

He said: “Together with other local authorities on the rail route between Abbey Wood and Gravesend, we have submitted what we believe is a compelling business case for the extension of the Elizabeth Line to Gravesham.

“The economic benefits this would bring to the borough and the potential to unlock and support new jobs and the development of the new homes we need to meet current government targets are entirely in line with the government’s own levelling-up agenda.

No decision has yet been taken on the bid but Cllr Burden added that he hoped for a "speedy and positive response from ministers".

Meanwhile, Dartford council leader Jeremy Kite also remains in favour of welcoming the scheme to Dartford.

But the Tory counterpart was cautious when it came to associated housing demand.

Cllr Kite said: "We have an interest in bringing Crossrail to Dartford but not if the price of doing that is lots of extra houses.

"We would love to have Crossrail but not at any cost."

Explaining his reasons, Cllr Kite said he was wary of "ending up like Lewisham" and south east London boroughs which had seen stations surrounded by large-scale high-rise developments.

Cllr Kite added: "We are having to put in a caveat which is we will welcome Crossrail if it does not lead to the overgeneration of buildings. We are not going to sell out the town."

However, it remains unclear if approved where the level of funding needed would come from.

In a Bexley council report published in November the council leader conceded "there may not be further progress until Transport for London’s future funding arrangements are determined".

The Mayor of London has previously backed an extension in principle but has not pledged any additional funding towards it.

In 2020, Kent County Council (KCC) launched its rail action plan for 2021 to 2030 stating its intention to provide a "substantial contribution" towards public transport infrastructure in north Kent.

This includes the likely extension of London's Crossrail service from Abbey Wood to Ebbsfleet, Swanscombe and Gravesend.

Kent's transport planner alluded to an expansion but said it could be financially dependent on contributions from the London Resort theme park which is earmarked to be built close-by.

However, concerns have been raised about the impact of the multi-billion pound entertainment centre on existing transport infrastructure in the area, including motorways, local roads, and train stations, including Ebbsfleet and Swanscombe.

In a further twist, plans for the London Resort – to be built on parts of a protected nature site – were withdrawn as a result of the classification of Tilbury as a new Freeport.

Even if funding can be secured, proposals for an extended Elizabeth Line are unlikely to be delivered before the mid-2030s at the very earliest.

The future of train services in Kent including Eurostar services at Ebbsfleet also remains uncertain.

Crossrail is being launched in three separate sections.

The next section is expected to be in autumn 2022 when services from Reading and Heathrow will operate through central London and access the new Elizabeth Line central section stations to Abbey Wood.

The final milestone will be no later than May 2023 when the final timetable will be in place.

Speaking ahead of the opening, Boris Johnson said: “We’ve completed Crossrail but frankly there is more that we should be doing.”