The inspections will “serve as a warning to employers that they cannot ignore the workplace pension and that deliberate non-compliance will not be tolerated”, officials said.

Meanwhile, financial advisory firm Wealthcare warned over ill-prepared businesses. It carried out research, which found more than four out of 10 small firms, have been waiting until the last minute to sign up their employees to an auto enrolment pension scheme.

Stephen Cainer, joint managing director of Wealthcare, said: “Our figures show there is still an alarming lack of preparation on the part of employers around the UK.

“Auto enrolment is a legal duty for employers to enrol their staff in a workplace pension scheme and pay contributions. The earlier they prepare, the smoother the transition will be. Planning in advance is essential.”

Firms which fail to comply with their auto enrolment responsibilities risk being fined. Up to December 2016, the regulator had issued 31,680 compliance notices and 9,831 fixed penalty notices.

TPR said the spot checks would also help employers get back on track or take enforcement action where necessary. It pointed out that compliance remains in the high nineties.

Employers will be given a short period of notice before the inspection, the regulator stated.

Executive Director of Automatic Enrolment Charles Counsell said: “It is important employers continue to make contributions into their staff’s pensions and these spot checks make sure ongoing compliance is being maintained. It is not fair to staff if they do not get the pensions contributions they are entitled to by law. We take non-compliance seriously and will take enforcement action when we need to.”

Mr Counsell added: “As well as investigating any non-compliance, these inspections will also help shine a light on employer behaviour so we can see why different types of employers fail and also identify good practice that others can learn from.”