sell the pass

sell the pass

BRITISH, OLD-FASHIONED
If someone sells the pass, they harm someone by giving an enemy or opponent what they wanted. The committee was widely blamed for selling the pass at a public enquiry which enabled a new motorway to be built over the site of the battle of Naseby. The Prime Minister sold the pass in an astonishing speech backing hospitals against patients. Note: This expression relates to a story in Irish history. The soldiers of Crotha, Lord of Atha, were blocking a pass between the mountains, against the enemy army of Trathal, the King of Cael. One of Crotha's soldiers was bribed to let Trathal's army through, and so he `sold the pass'. Because of this, Trathal's army invaded successfully, and Trathal became king of all Ireland.
See also: pass, sell

sell the pass

betray a cause. British
As in head someone off at the pass above, pass is here used in the sense of a narrow route through mountains, viewed as a strategic point in time of war. Selling the pass was supplying information to the enemy that would enable them to circumvent or otherwise get through the obstacle (turn the pass ). In the mid 19th century it was considered to be an Irish expression meaning ‘betray your fellow countrymen by selling information to the authorities’.
1996 Economist Having sold the pass on the referendum, will he really be able to hold the pass on responsible economics?
See also: pass, sell