IDIOMS

under the pump

(Australia) Under pressure to perform.

Example: Used other than as an idiom: see under,‎ pump.
1839, “Captain Marryat”, A Diary in America, with Remarks on its Institutions, page 159,
  The laws of the state relative to the intermarriage of the whites with the coloured population, are also referred to. A case of this kind took place at New York when I was there; and as soon as the ceremony was over, the husband, I believe it was, but either the husband or the wife, was seized by the mob and put under the pump for half an hour.
1863, “Mrs. Lovechild”, The Truant, in The Christmas Tree and Other Stories for the Young, page 48,
  Now the punishment for playing truant was to have the truant′s head put under the pump, and pumped upon.
1867, New Zealand Parliament, Parliamentary Debates, Volume 1, Part 1: 9 July - 9 August 1867, page 106,
  The unfortunate individual was of course immediately taken, put under the pump, and soundly pumped upon. This was the sort of conduct adopted by the honorable member for the gold fields and his friends.
1995, Graham Chainey, A Literary History of Cambridge, page 201,
  […] claim that when he was at Oxford ‘Socialists were put under the pump’.
2003, Harry Gordon, The Time of Our Lives: Inside the Sydney Olympics, page 13,
  Nick was under the pump. He was underdone, and the selectors wanted to replace him with James Stewart.
c. 1970s, Doug Walters, quoted in 2008, Ashley Mallett, One of a Kind: The Doug Walters Story, 2010, ReadHowYouWant, page 219,
  I think all the Australian batsmen who came back from South Africa felt a bit under the pump. We simply had to perform or not stay in the side.