More and more Tube staff are turning up for work under the influence of drink or drugs, BBC London has learned.
The increase reflects a national trend, says Mr Radcliffe
London Underground, which has a "zero tolerance" approach to alcohol in the bloodstream, is looking at increasing random testing of employees.
Last year, 1,150 people were tested on the job and eight failed. This year 1,100 were tested and 27 failed.
Counsellor Nigel Radcliffe said staff affected by the 7 July attacks were already presenting with drink problems.
But he told BBC London he did not think drink problems were just a problem among Tube staff.
"I have been aware that what we are picking up at London Underground reflects what's going on in wider society, particularly within urban areas and with working people," he said.
"It reflects the national experience, it's just sharpened in that we are picking it up a long time before anyone else."
Last year, several Tube workers were sacked after 86 beer cans and an empty cognac bottle were found at Farringdon underground station.
Louella Johnson, from LU, said: "There's been an increase in last year's figures to the year ending March 2005 and we have responded to that.
"We will be looking at the way we train managers, we will look at the way we communicate the policy and we will increase the level of testing that we do."