The specific answer to your question is in paragraph 4.1 of
AIC 95/2008, which reflects pages 2-2-3-1/2/3 of
ENR 2.2 in the UKAIP.
The short answer is that you may transit the MATZ but you should remain clear of the ATZ, which will probably still be active. You may cross above the ATZ, which extends up to 2000' aal, but should not infringe it without specific clearance to do so. Listening watch and/or blind calls within the MATZ (but outside the ATZ) are entirely optional for civil aircraft.
Hope this helps ...
JD
