Formula 1's Strategy Group has voted against the introduction of the Halo head protection device for the 2017 season.

But the Halo could still be introduced for the 2018 campaign after F1's stakeholders "agreed unanimously" that cockpit protection will be introduced from the season after next.

The Halo remains "a strong option" and more tests will be carried out in practice sessions, but the Strategy Group decided more time was needed to evaluate all potential solutions.

The group has also agreed to lift the unpopular restrictions on radio messages from this weekend's German GP.

The 18 votes of the Strategy Group are split between three parties - the teams, the FIA and the Formula One Management group.

Six teams - Mercedes, Ferrari, McLaren, Red Bull, Williams and Force India - hold one vote each, while Bernie Ecclestone casts six on behalf of FOM as does Jean Todt, the FIA president, for the governing body.

Ecclestone is a known opponent to the Halo while Red Bull boss Christian Horner recently described it as "an inelegant solution to the problem it is trying to deal with".

Red Bull became the first team other than Ferrari to run the Halo when they fitted the device during the Silverstone test Red Bull became the first team other than Ferrari to run the Halo when they fitted the device during the Silverstone test

Critics have opposed the introduction of the Halo on grounds of aesthetics and philosophy - F1 has operated as an open-cockpit formula throughout its existence.

Lewis Hamilton was previously a vocal critic of the concept, describing the Halo earlier this year as the "worst-looking mod in F1 history".

But after what the world champion described as "a great briefing" for the drivers at the Hungarian GP, Hamilton said: "They said there is a 17% improvement on life saving. We can't ignore that. It's a safety thing that we all have to accept."

Ferrari's revised Halo cockpit head-protection system made its debut in the opening practice session of the the British Grand Prix at Silverstone Ferrari's revised Halo cockpit head-protection system made its debut in the opening practice session of the the British Grand Prix at Silverstone

Ferrari driver Sebastian Vettel has led calls for the Halo's introduction and said on Thursday: "I don't like the way it looks but nothing justifies death."

Vettel tested the device in practice at Silverstone this month, after which he admitted it had "quite a lot of impact in terms of visibility."

But after trying out the Halo in Mercedes' simulator, Sky F1's Anthony Davidson said: "The central support was a mild distraction in the virtual world at least. I think in reality you will get used to it, just like you get used to a central windscreen wiper being there on a sports car. It is amazing how you adapt and get used to things."

FIA statement in full

Frontal cockpit protection

'The Strategy Group agreed unanimously that the 2018 season will see the introduction of frontal cockpit protection for Formula One cars in order to significantly enhance the safety of drivers.

'It was decided that owing to the relatively short timeframe until the commencement of the 2017 Formula One season it would be prudent to use the remainder of this year and early next year to further evaluate the full potential of all options before final confirmation.

'This will include undertaking multiple on-track tests of the 'Halo' system in practice sessions during the rest of this season and during the first part of the 2017 season.

'While the Halo is currently the preferred option, as it provides the broadest solution to date, the consensus among the Strategy Group was that another year of development could result in an even more complete solution.

'Halo remains a strong option for introduction in 2018.'

Radio communication

'At the request of the Teams and Commercial Rights Holder, the FIA has agreed to adopt a more liberal approach to the interpretation of Article 27.1 (that a driver must drive the car "alone and unaided").

'With the exception of the period between the start of the formation lap and the start of the race, there will be no limitations on messages teams send to their drivers either by radio or pit board.

'This approach is aimed at providing improved content for fans and spectators, as teams will now be required to provide the Commercial Rights Holder with unrestricted access to their radio messages at all times that their cars are out of the garage.'