Leader of the Commons Andrea Leadsom told MPs the current system for dealing with complaints is "inadequate" and that failure to respond properly risks bringing Westminster into disrepute.
It came as Downing Street refused to give its support to a minister under investigation for making lewd comments towards a personal assistant and sending her to buy sex toys.
"As MPs, our constituents will be rightly appalled at the thought that some representatives in Parliament may have acted in an entirely inappropriate way towards others," Ms Leadsom told the Commons. "These reports risk bringing all of our offices into disrepute."
Mr Bercow said he was open to the creation of a new parliamentary body to police complaints of harassment, but added: "In the first instance I hope that parties will live up to their responsibilities, demonstrating both an appetite for change and a practical means of delivering that change without delay. Make no mistake, there is a need for change."
Theresa May sat next to Ms Leadsom on the front bench throughout the statement, which was also heard by Jeremy Corbyn and SNP Westminster leader Ian Blackford. Labour and the SNP both gave their support a beefed-up independent complaints service, which will support staff who suffer the most serious sexual assaults to make reports to the police.
Several MPs suggested staff who had concerns about the way they were treated had little confidence in Westminster authorities. The Labour MP Chi Onwurah claimed that when she raised complaints by junior researchers about the conduct of MPs in Sports and Social, one of the bars on the parliamentary estate, authorities told her that was what happens in pubs across the country.
Ms Leadsom revealed that she would be meeting with those responsible for managing the estate to discuss conduct in Sports and Social on Tuesday. She said there was a vital need for better support and protection for thousands of people working in the Palace and that action was needed "in days rather than weeks".
The statement came in response to an urgent question from Labour MP Harriet Harman following a rash of media reports about alleged misconduct by MPs, including international trade minister Mark Garnier.
Earlier, the Prime Minister's spokesman refused to say whether Theresa May has confidence in Mr Garnier, who is alleged to have called his personal assistant "sugar t***" and waited outside while she was sent into a sex shop.
The Cabinet Office is investigating whether Mr Garnier broke the ministerial code through his conduct, which he has apologized for and described as "high jinx".
Mrs May's spokesman said he would not comment on Mr Garnier's position until the investigation had concluded. Addressing MPs, Ms Leadsom said any minister found to have sexually harassed staff should lose their job.