The government could force employers to take staff complaints to independent mediators as it bids to cut the number of cases going to tribunals.
Michael Gibbons, whose 2007 report led to the creation of a new dispute resolution system through the Employment Bill, warned that tougher measures were possible.
When the Bill comes into force in April, the much disparaged statutory dispute resolution regulations will be replaced with a more flexible Acas code of practice.
But Gibbons told Personnel Today: "The ultimate risk is that the hope we have of reducing the number of cases at tribunal is not fulfilled. If there is an unwanted increase in tribunal claims, no-one is going to change their mind about the direction we are going in.
"If there has not been great success then we have to find new ways of enforcing these messages. A potential answer is what New Zealand and South Africa do, which is to make mediation mandatory."
The Gibbons Review found that the 2004 dispute resolution regulations were unpopular with both employers and trade unions, and had led to an increase in formal conflicts.
Gibbons said he was happy with the Employment Bill, which takes on most of his recommendations and encourages employers to follow a 43-point Acas code – making tribunals a last resort.
Speaking at a seminar hosted by manufacturing employers' group EEF in London last week, Gibbons said he was hopeful the Bill would give employers more chance to settle disputes quickly, cheaply and effectively.
The Department for Business, Enterprise and Regulatory Reform insisted it had no plans to revisit dispute resolution.