Full maternity pay should be tripled according to the European Union (EU), increasing the current amount offered from six to 18 weeks.
The government has claimed the move could cripple businesses already struggling in the recession, and has asked the EU to clarify its proposal.
Employers currently pay mothers 90% of their salary for six weeks, then £117 a week for 33 weeks (roughly nine months) thereafter.
The pay was due to be increased to £123.06 a week under new law by 2010, but this is likely to be postponed to help firms survive the economic crisis.
A Department for Business spokseman said any further increases, even if they included a 'ceiling' limit, were unrealistic in the current climate.
"The proposals include a requirement for full pay [to increase] during maternity leave, albeit subject to a ceiling. There is a lack of clarity in this proposal which could expose the UK and other member states to serious additional costs," he said.
The department also claimed that the UK's maternity pay was already both "generous" and "progressive".
But equality experts have claimed that improved payments could help women to feel valued by their employers and not forgotten when on leave. This, in turn, could persuade new mothers to return to work, saving UK employers re-recruitment and training costs.
Andrea Ward, employment associate at the law firm Hogan & Hartson, explained: "Although there will be increased costs for businesses, an uplift on maternity pay to support women during such an important time may well encourage them back to work and save employers money in the long run."