WW 2 awards for Royal Navy Diving , Bomb and Mine Disposal. http://www.mcdoa.org.uk/ww_ii_awards_for_rn_diving_b_and_md_H.htm
As below there are a number of P parties mentioned. The Royal Marines were RM Engineers rather than Commando engineers, each company having a port clearance diving party and mine EOD team. P parties were large organisations drawn from the RME RN and some members of the Royal Engineers on as "as required" basis. Most had an NP Number MUIR Alexander Gunning PO/X110265 A/Cpl RM 'P' Party 1574 15 May 45 BEM Port Clearance - BEM awarded for gallantry and skill in mine-searching and clearing operations in the ports of Normandy and of the Low Countries following the invasion of France.