However, the Federation of Small Business (FSB) believes that the move could encourage small businesses to employ more staff.

The government is currently reviewing business regulations, with a view to simplifying working practices for smaller businesses. Last week, it announced a number of tax alterations that were under consideration.

Business secretary Vince Cable has also now said that an additional range of measures are being investigated.

Cable said: "It is not right that businesses should have to deal with years of government intervention by abiding by arcane rules."

One of the key moves will see the right to time off for training not extended to businesses with less than 250 employees.

Unite said that there was "absolutely no sensible reason" for millions of employees to be denied the right to request training because of the size of their employer.

Assistant general secretary Tony Burke said: "This government seems to think growth equates to attacking workers' rights. The better trained a worker, the more Britain benefits but Vince Cable would rather give bad employers who don’t want to train their workforce properly a nudge and a wink.

"Britain needs a skilled workforce that is constantly learning if we are to generate growth, innovate and compete in the global economy. The business secretary should be thinking long term. Instead, he is keeping the business lobby happy with short-term cost-cutting measures, which Britain will eventually have to pay for as we watch our competitors leave us for dust."

Andrew Cave, FSB spokesman, said: "These changes will provide stability to businesses – it is likely to lead more employers to take on additional staff.

"It is a well-known fact that small businesses are the most flexible employers, their staff are often happier due to the closer working relationships. This is simply about removing the tick-box exercises that can confuse potential employers."