I was often in dispute with my Manager over my concern with the Tyres on my van when I was working,often with tread issues similar or worse than that you have posted it got that bad in the end I point blank refused to take the van out,from experience I can tell you that if you were to report them to a higher person in your company even putting it in writing and you get pulled by the boys in blue they will still penalise you as the be all and end all as the onus is sat squarely on your shoulders as You are responsible the minute you drive on the highway,they may to some look okay but you get an copper on a bad day and boom points on licence and fines,if you can take it to an MOT station and ask there opinion.