Hi Jose,
I recommend this email:
Dear Sir/Madam,
We recently updated our 'critical materials' list. The most urgently needed materials are highlighted in red.
We are aware that there is a lack of stock, as well as a big demand for these items. However, in some cases the lead times are much too long. As a result there is increasing dissatisfaction among customers regarding incorrect delivery dates and a lack of information in general.
We kindly ask that you check on current availability of these materials in your central warehouse. Moreover, do you happen to know when this problem will be resolved?