Health minister Rosie Winterton told HSJ there will be no concessions after the House of Lords tried to change crucial parts.
She said: 'We've already made considerable changes. Now the balance is right between modernising legislation, public protection and increasing patient safeguards.
'We want people to work in mental health because of new ways of working and don't want to see that put back in any way.'
National mental health director Professor Louis Appleby spoke alongside Ms Winterton and took the opportunity to defend controversial supervised community treatment orders (SCTOs).
These would release inpatients and place them under strict control in the community, but opponents fear too many will face compulsory treatment for lengthy periods.
Professor Appleby said: 'SCTOs are used in countries around the world - not one of them is thinking about repealing the legislation.'
But mental health campaigners are warning that the legislation would compromise patient care.
Rethink chief executive Paul Jenkins said ignoring the amendments 'would be a step backwards for a government that has done an awful lot for people with mental health problems'.