The government is to give gig economy workers new rights including holiday and sick pay for the first time.
Its Good Work plan is in answer to last year's Taylor Review which recommended changes in conditions to reflect modern working practices.
The government has adopted nearly all the review's recommendations.
But unions have said the plan will still leave 1.8 million workers without key rights.
The Taylor Review concentrated particularly on the so-called gig economy of part time and flexible workers. It said all work in the UK economy should be "fair and decent".
The government says it is going further than the Review's recommendations by:
- Enforcing holiday and sick pay entitlements
- Giving all workers the right to demand a payslip
- Allowing flexible workers to demand more stable contracts
It says it will now monitor and report on the quality as well as the quantity of jobs in the economy and take steps to make sure flexible workers are aware of their rights.
It is also asking the Low Pay Commission to consider a higher minimum wage for workers on zero-hour contracts, and says it may also repeal laws that allow agencies to employ workers on cheaper rates.
The Prime Minister Theresa May said "We are proud to have record levels of employment in this country but we must also ensure that workers' rights are always upheld. Our response to this report will mean tangible progress towards that goal as we build an economy that works for everyone."
Matthew Taylor, the author of the original review, called the government's response "substantive and comprehensive".
He said: "It will make a difference to the lives of the most vulnerable workers and that is what matters.
"I welcome the range of specific commitments to improve the protections and rights of workers and to enforce those rights more strongly.
"On important issues, including pay for variable hours workers, employment status and representation of workers I welcome the direction indicated today, but there is more work to be done to encourage the Government to be bold in living up to its commitment to good work for all."
Richard Laughton, Sharing Economy UK Chair, the trade body for the sharing economy industry, said firms welcomed the government's plan.
"Many people hugely value the flexibility that platforms provide and have been able to participate in the employment market for the first time.
"Greater clarity on knowing when they are to be paid will help individuals make informed choices."
Mr Laughton who is also chief executive of easyCar, added: "It's essential that updates to the UK's labour market continue to promote entrepreneurship, encourage participation and maintain flexibility while helping to develop skills."
Light on substance
However, unions have been far more critical. Dr. Jason Moyer-Lee, General Secretary of the Independent Workers Union of Great Britain (IWGB) said: "Like the Taylor Review, it so far appears big on grandiose claims, light on substance.
"The most important single thing government could do is introduce effective government enforcement of employment law. They say they will do this but give no indication of how."
TUC General Secretary Frances O'Grady added: "The government has taken a baby step - when it needed to take a giant leap.
"These plans won't stop the hire and fire culture of zero-hours contracts or sham self-employment. And they will still leave 1.8 million workers excluded from key protections.