Tory MP William Wragg, one of those calling on the PM to resign, said rebels had faced "pressures and intimidation" from ministers.
And he claimed suspected plotters had been threatened with damaging publicity tantamount to blackmail.
No 10 said it was "not aware of any evidence" for Mr Wragg's allegations.
"If there is any evidence to support these claims we would look at it very carefully," a Downing Street spokesperson added.
Could be horses heads on the pillows of a few of these plotters in the morning.
And he claimed suspected plotters had been threatened with damaging publicity tantamount to blackmail.
No 10 said it was "not aware of any evidence" for Mr Wragg's allegations.
"If there is any evidence to support these claims we would look at it very carefully," a Downing Street spokesperson added.
Could be horses heads on the pillows of a few of these plotters in the morning.