Patricia Kirwan, the former Conservative chair of housing on Westminster City Council, said:
'Officers were being bullied into doing work which was political because they were frightened of their jobs and getting the sack.
'I didn't think that they should be asked to write political papers.'
The duo, and eight others, have been accused of squandering £21m by selling off council homes at a discount to entice likely Tory voters into marginal wards.
Mrs Kirwan is a key witness since she was the first senior Westminster Tory councillor to blow the whistle on the alleged 'homes-for-votes' plot.
She had opposed the scheme to sell off many of the council's homes and had also fallen out with Dame Shirley.
She told the inquiry that the scheme was 'drawn up with a view to increasing the Tory vote in eight key marginal wards - that was wrong.'
She added that the sales of the homes were aimed 'at the sort of person who would be more likely to vote Conservative.'
She alleged that Dame Shirley 'hammered councillors into the ground' to produce a scheme to 'gentrify' the marginal wards.
She said that as chair of housing, she was under pressure from the leadership to write papers on how to angle housing policies at marginal wards.
She claimed that she mentioned marginal wards in these papers as a 'sop' to 'keep Dame Shirley off my back for a while.'
'Marginal wards was the in-word at the time,' she added.
However, she was opposed to targeting just the key wards because 'it was crass politically to ignore the other wards and write them off.'
Mrs Kirwan stood against Dame Shirley for the post of leader because she 'didn't like her style, her attitude and way of working.'
After Mrs Kirwan lost, she was treated like a leper' and relegated to the 'back of the backbenches.'