 Complete the following phrase:  On 2 May, German air activity increased. Intelligence gathered from prisoners and deserters stated an attack would occur around 9 May. In response, the divisional artillery increased their shelling of German positions. This resulted in the destruction of an ammunition dump on 8 May, and of a church used as an observation post the next day. By 15 May, no attack had materialised; per Coop, the result of Spanish flu spreading among the Germans. Between 4 and 5 June, the Germans bombarded Beuvry, Givenchy, and Labourse with Yellow Cross gas shells. Prisoners again reported an impending attack, but it likewise did not take place. On 8 June, the division conducted a raid on their German counterparts to gather intelligence, but the attack was repulsed. With the exception of sporadic raiding, the sector remained quiet. Also in June, Major Clement Attlee, who was later Prime Minister of the United Kingdom from 1945 to 1951, joined the 15SL, having previously served at Gallipoli and in 