The Government is pressing ahead with plans to allow local councils to extend Sunday trading hours.
Amendments to the Enterprise Bill will be introduced to enable the change in hours to be made in the autumn.
Ministers said that local retailers will have the flexibility to adjust hours so they can compete for trade.
Business Minister Anna Soubry said: "Extending Sunday shopping hours has the potential to help businesses and high streets better compete as our shopping habits change.
"The rights of shop workers are key to making these changes work in everyone's interests. We are protecting those who do not wish to work Sundays, and those who do not want to work more than their normal Sunday working hours."
The shopworkers' union Usdaw has warned that the move will mean staff will have less time to spend with their families and could put small stores out of business.
Under measures to devolve Sunday trading laws to local authorities, councils will be allowed to "zone" any relaxation so they will be able to prioritise high streets and city centres.
Ministers said the measures include greater freedoms for shopworkers in England, Scotland and Wales to opt-out of working Sundays if they choose to, for example because they object on religious grounds or for family reasons.
Shopworkers will be able to give one month's notice to large shops that they no longer want to work Sundays, down from three months, and will have a new right to opt out of working additional hours.
The Government said it will also strengthen the duty on employers to notify employees of their rights about working on Sundays.
Usdaw general secretary John Hannett said: "Devolving Sunday trading to over 300 local authorities will strangle the retail industry in red tape. What the Government is proposing is undesirable and unworkable.
"Their claims to be offering additional protection for shopworkers amounts to nothing more than has existed for the last 20 years. 91% of our members working in retail oppose longer Sunday trading because they know it will have an adverse effect on family life and put them under even more pressure to work longer hours on a Sunday.
"The Government has delayed publishing their amendments until the last minute, having not put the changes in the Devolution Bill. They haven't published the responses to the consultation because they know there is large scale opposition to devolution of Sunday trading from retailers, shopworkers and the wider community who want Sunday to remain different.
"The Sunday Trading Act is a great British compromise, which has worked well for over 20 years and gives everyone a little bit of what they want. Retailers can trade, customers can shop, staff can work; whilst Sunday remains a special day, different to other days, and shopworkers can spend some time with their family."
Tory backbencher David Burrowes said: "The Government should still listen to the significant opposition to this unnecessary and unwanted plan.
"Otherwise I look forward to leading an unholy cross-party alliance in defeating a measure which is anti-family, anti-small business and anti-workers."