The British Grand Prix is the only race UK viewers will be able to watch on free-to-air television

Formula 1's relationship with the British public undergoes a huge shift this year.

For the first time in more than 40 years, audiences in the UK will not be able to watch regular live coverage of the F1 season as part of their basic television package.

The only race available to watch live on free-to-air television - requiring only a licence fee - will be the British Grand Prix.

Britain's five-time world champion Lewis Hamilton said during pre-season testing that this development was "definitely not cool", as he recalled settling down to watch grands prix live as a child.

It is the result of a new contract between F1 and pay-television company Sky, which was signed by former F1 boss Bernie Ecclestone before the sport was sold to Liberty Media.

This contract runs from 2019 to 2024 and it hands Sky the exclusive broadcast rights to F1 in the UK.

The deal contains a requirement that the British Grand Prix and extended highlights of the remaining races must be on free-to-air television. But it is for Sky to decide where, as long as the outlet satisfies the contractual requirement for "90% technical availability". This basically means it has to be a channel on Freeview/Freesat.

For 2019, Sky has opted to do a deal with Channel 4, which from 2016 took over the former BBC contract to show about half the races live and the others as highlights. No decision has been made on 2020 onwards.

What will the free-to-air package look like?

British racing driver Billy Monger will be joining Channel 4's coverage of the 2019 season

Channel 4 last year had 65.7% of the total audience watching F1 in the UK, according to the sport's official figures. It says its average audience for live race coverage - lights to flag - was 2.9m. For the entire live race programme, the average was 2.5m.

It is aiming to keep its programming as recognisable and distinctive as possible, despite the loss of live race coverage.

The on-air line-up remains pretty much the same. The most high-profile figures - presenter Steve Jones, analysts David Coulthard and Mark Webber, and commentator Ben Edwards - are still on board.

The only on-air personnel to leave are former racing drivers Karun Chandhok and Susie Wolff. Chandhok has moved to Sky, while Wolff is concentrating on her business interests, including running the Venturi Formula E team. It has added Billy Monger, the 19-year-old British racing driver who lost his legs in a crash in 2017.

And Stefano Domenicali - Ferrari team principal from 2008-2014 and now chief executive of Lamborghini - will be a pundit for an unspecified number of races.

Sky has imposed a series of restrictions on C4 in the contract for the highlights races, which will affect both the race coverage itself, and what happens around it.

For example, only 50% of the total running time of C4's programme can now be taken up by the on-track coverage - down from between 60-70% last year. They are not allowed to do interviews in what is known as the 'pen' - where all the drivers are taken to do a round-robin of broadcasters after qualifying and race - or in the pit lane. Any 'pen' interviews they use will have to come from Sky. The amount of interviews C4 can do in the paddock is restricted. And they have been forbidden from doing a 'grid walk'.

None of these restrictions apply to the live British Grand Prix.

In addition, the highlights programmes can now not start until a minimum of three hours after the race, although this could be a blessing in disguise as it pushes them into evening prime time, when audiences are potentially bigger.

C4 intends for its programme to retain its broad appeal. Like the BBC before, it has always aimed to produce something that can be enjoyed by both the less-committed casual audience and hardcore fans.

The Sky offering

Jenson Button had 50 F1 podium finishes and won the World Championship in 2009

Sky wants to set itself up as the go-to place for F1 in the UK.

Last year, it had 34.3% of the total UK F1 audience, and the number of people watching its live coverage grew by 21.9% over 2017.

Its average audience for its live race programme was 707,000, according to official F1 figures, which measure across the broadcast, so will come up lower than just the race action itself. There have been peaks over 1m on occasions. Sky would not provide exact figures.

Its presenting team remains pretty much as was, other than the addition of 2009 world champion Jenson Button, for some races, and Chandhok for the vast majority.

The Sky deal is worth a reputed £1.2bn to F1 over its duration. That means income from Sky UK alone amounts to about 11% of F1's turnover and Sky has effectively become the sport's biggest single sponsor.

Insiders expect Sky's vast investment to buy it some freedom from the restrictions imposed on broadcasters in their contracts. Sources say it is planning a studio in the paddock at the European races, for example, although Sky would not confirm this. F1 chief executive Chase Carey, incidentally, is on the board of Sky UK.

Sky would not share its plans for where it will broadcast F1 other than its dedicated channel, but it will show the season-opening Australian Grand Prix - and quite possibly each of the first three races - on Sky One, which increases the audience.

As for the future of the free-to-air aspect of the deal, Sky is said to remain open-minded. It has two options - strike another deal with a major free-to-air channel such as C4, or put it on one of its own channels on Freeview, the most high-profile being Pick.

Sky is expected to trial a bunch of races on Pick as a tester this year, but as long as C4 sticks to the terms of its contract and works with Sky rather than against it, Sky is said to be not opposed at this stage to that relationship continuing into 2020.

What does this mean for F1 and UK audiences?

The risk for F1 in this new arrangement is that UK audiences drop substantially.

No matter what Sky does with its programming, it would be highly unlikely, based on past evidence, to get close to replacing all the free-to-air audience. If Sky achieved another 21.9% growth in live audience, it would rise to 862,000. That would be a drop of more than 58% from 2018 to 2019.

Not many sports have thrived in terms of audience and public engagement when they go solely to pay TV.

Football continues to generate massive interest despite the Premier League being shown live only on pay TV, with highlights on free-to-air, via Match of the Day.

But football is the exception to the general rule.

Liberty has always emphasised that it sees the future of broadcasting in F1 as a combination between free-to-air, pay TV and what it calls OTT, or direct-to-consumer over the internet.

In other countries, F1 is already running an OTT platform. But this is not possible in the UK because the Sky contract forbids it. The earliest the UK can have F1 TV, as it is known, is 2025.

But OTT will not appeal to everyone, and it remains unclear whether it will attract casual audiences.

It is another form of pay TV. It requires the audience to know about it and go and seek it out. And there are questions over the level of appeal when a sport provides its own editorial content, with the inevitable impact on the independence of the coverage.

The risks of sports going pay TV only are well established: many people simply won't be prepared to pay the money to watch; and it limits the chances of a casual audience finding it.

Social media has made an impact in terms of broadening the number of ways people might come across F1 - and in keeping gross audience figures high. But even if seeing content clips on the internet piques people's interest, the barriers to watching extensive amounts of F1, and thereby creating new and committed fans, remain if the sport is solely on pay TV.

Lower viewing figures also make it harder for teams to sell themselves to potential sponsors - already a difficult task in the current global financial climate. And fewer people watching reduces the appeal of F1 to major participants such as Mercedes, Ferrari, Renault, Honda and Red Bull, who are in it for the global exposure it gives their brands.

A reduced audience has other potential knock-on effects. A smaller audience means less interest and potentially declining participation levels. Which could restrict the number of aspiring racing drivers, engineers, mechanics and so on in a country that has been the epicentre of F1 for decades.

F1 is taking a step into the unknown. The sport will make more money as a result, but the effects on its long-term health in the UK remain to be seen.

All times GMT and are subject to change at short notice.