Nico Rosberg is the latest of a group of drivers to express concerns about the ban on tyre warmers in Formula One next season, labelling as "ridiculous" the way his car handled on cold slick tyres.
Blankets to warm tyres up will be outlawed from next season and that, combined with the fact that cars will generate a lot less downforce due to new regulations that will come into play, is likely to make driving tricky until the tyres are up to the right temperature.
Several teams have been testing the new slicks with simulated 2009 aero configurations at Barcelona this week, and some drivers reckon downforce levels are down by 40 to 50 percent with those settings.
Grand Prix Drivers' Association president Pedro de la Rosa said on Monday the speed differential between cars already up to racing speed and temperature and those running on cold tyres was a worry for next season.
"The first lap is very slow, and that's the danger," said McLaren test driver de la Rosa.
"There are cars which are up to racing speed and you are coming out of the pits very slowly. You are like a mobile chicane."
Bridgestone has introduced a new, softer compound for this week's test after running with the slicks for the first time at Jerez in December.
Drivers seemed to be generally happier with the new tyres introduced in Spain, but the difference in track temperature from December to April will have also played a role in making the driving on cold rubber easier.
Rosberg said that completing the first lap on cold tyres was a matter of "survival".
"First of all it's still not good. It's still not right," Rosberg told autosport.com at Barcelona after testing the slick tyres. "You can't run tyres like this next year. That's my opinion, definitely not. It's ridiculous. Running out of the pits it's ridiculous.
"It's not racing, it's survival. It's just survival out there, and that's ridiculous, it's not racing.
"They have to do something on the tyres to improve that. It's not the way it should be. You can have cold tyres, but not like that."
Rosberg, who had also sampled the slicks in the first test in Jerez, said the new compound made things easier.
"Yeah, but it's 20 degrees hotter (at Barcelona). There's going to be races with where we won't have these temperatures," he added.
The Williams driver said the GPDA is likely to urge for changes in order to improve the situation.
"That's what the GPDA is for. I'm sure we'll try to push something. I'm not saying tyre warmers, but I'm sure we'll try to have an influence all together."
Honda driver Rubens Barrichello was also critical of the regulations, and believes they are also likely to be bad for the show.
The Brazilian said the tyre blankets ban was a step backwards for the sport.
"It's a bit too early to say things but I follow what de la Rosa said," Barrichello told autosport.com. "Without the blankets racing might be a bit boring, because then people will want to go as long as possible, as you are going to lose three seconds out of the pits.
"We may have crashes on the out lap because people may be trying things and I just don't think that's nice.
"What we could do then is make harder tyres with a little bit of blanket. Off the top of my mind, if the FIA supplied a tyre blanket with a maximum temperature. Let's say 50 degrees. Anything better than none.
"You could go to Malaysia and it would be better. But if you have a safety car with a tyre like this...
"As racing drivers we know we can get used to things, so it's not a problem. But I think for the show it's not going to be nice. It's just not needed. We are going back. It's going to be like Champ Cars."
Bridgestone is expected to test slick tyres again this season in July.