I was in our local supermarket today and saw that the frozen foods cabinet had 8 new tubes fitted but instead of nice bright light they were all dim and flickering they had been lit for several hours so it can't be a warm up time do you think the tubes were suffering from cold or just a bad batch. The tubes were spread over 4 freezers each physically seperat from the next although they share the same mains supply

This happens a lot where I live so they just retrofitted it to LEDs. I have thrown rapid start fixtures with tubes into the freezer and this happened. Preheat seems more reliable in the cold. They also make special ballasts and bulbs rated for low temps. Most rapid start ballasts aren't rated for below 50° f.

This may also happen if the rapid start fixture is un or improperly grounded.

The RS is rather problematic concept: To work as wanted, the ballast OCV has to be above the voltage required to strike the lamp with hot electrodes, but below the level allowing current to flow with cold electrodes (with the extra cathode fall). The problem is, that window is rather narrow. The external electrode (grounded reflector, conductive stripe or layer) helps to increase that window, but still the need to operate it over wide temperature closes it back down.
The normal ballasts are designed with lower OCV, so they are more immune towards lamps cold starting (that reduces their life). Plus lower OCV means lower ballast losses and cost.

For low temperature use, the OCV is made higher, the cost in ballast losses and lamp life (due to more frequent cold starts) is just accepted.

I'm not sure what type of fitting they are ad they are hidden behind plastic covers I think that as has been suggested they are just not getting to temperature. Maybe I should suggest taking all tubes out warming them on the shop then re installing them  in there freezers. It can't be down to bad grounding the cabinets are metal and if there was a problem all customers would get a tingle when they went to get there fish fingers!

I was responding mainly to those two pictures above...

If the lamps light along their complete length, but are just dim or even pink, then indeed it is the operating temperature too low. I would guess the freezer originally included some sort of covers on the lamps, but those covers probably got damaged or lost...

Sorry I just reread all the replies and now see!s obviouse that the fittings are rapidstart and are just struggling due to the temp in the freezers being well below 32 fahrenheit thanks for all your replies I do appre ozte your help

Normally they use high output or low temp rated tubes and ballasts for such applications. The county market in my area is like that, with dim pink tubes. Normally, they'd use instant start since the temp goes much below the rating for rapid start.