The Grand Prix Drivers' Association will have no hesitation in calling for a boycott of testing in the future if safety standards at venues are not up to scratch, autosport.com has learned.
That warning has come as the drivers' body calls for improvements to be made to Spanish testing venues Barcelona and Valencia.
The GPDA held a meeting at Jerez in Spain last night to discuss the latest developments in their crusade to get safety improvements. They want tests to have the same level of protection and medical facilities as Grand Prix events.
As autosport.com revealed last month, the GPDA had been primarily concerned about facilities at Jerez and had demanded improvements - especially to the medical centre. The circuit eventually agreed to complete the necessary work.
Those improvements were given the thumbs up by GPDA representative and Toyota doctor Riccardo Ceccarelli on Wednesday following a detailed inspection, with only minor issues now needing to be sorted.
However, other circuits were singled out by the GPDA in their meeting, and now improvements are being eyed at both Barcelona and Valencia.
Speaking to autosport.com at Jerez, GPDA chairman Ralf Schumacher said that the drivers wanted further safety work made at these tracks. And he warned that without the improvements, there would be the chance of drivers refusing to test there.
"There are issues at Barcelona and in Valencia," he said. "We will address them, as everyone is aware of the situation. We want to feel safe enough to go to them.
"If the work does not happen, then we will not go. It is as simple as that."
Schumacher, who took over the chairmanship of the GPDA at the Chinese Grand Prix, said it was important that the drivers' body stood up for what it believed in. And he felt it vital that he took the initiative personally to keep things moving forward.
"There are good reasons why we are doing these things," he explained. "There are things that are important that we are pushing for.
"Not all the drivers share the same interests, or want the same results, and not everyone is taking care of everything. That is why the chairman has to take care of it.
"The meeting here was very constructive. I asked for it, because we had never done it (had a meeting) apart from at a Grand Prix. So in a relaxed atmosphere we went through the tracks one by one.
"I think the GPDA has achieved something together with the FIA, which is good. It is important that we stick together and try to improve safety. At some test tracks the safety facilities and medical facilities were a joke - so even things like that have been achieved by the GPDA."
Schumacher praised Jerez's efforts to bring the circuit up to scratch, and said he was hopeful that other venues would show as much willingness to cooperate with the GPDA.
"Jerez has been very helpful and it has been inspected, and more or less they did everything we had asked them for," explained Schumacher. "We have some tiny details, but nothing of concern at the moment.
"But there are some other problems in other circuits that we were talking about in our meeting. But we are 100% positive that it will be done too."