Her Majesty's Revenue and Customs has given people filing their income tax returns online a reprieve and extended tonight's midnight deadline.

Problems started this morning when HMRC's self-assessment website went down. Although it has been working to get the site back up during the day, there were fears that many people would be left in limbo and unable to file their returns.

The Government department has just released a statement saying that the system is gradually coming back online.

“HMRC’s Self Assessment online filing service has experienced technical difficulties this morning which has meant that some tax payers have experienced difficulties filing online.

"The system is now rapidly returning to normal levels of service. A record number of 3.6 million taxpayers have already successfully filed online with 104,000 filing today," it said.

However, with the deadline for filing income tax returns and paying any tax due, being midnight tonight, many people feared they would be unable to access the service in time. For those who owed more than £100 in tax, this would generally mean an automatic fine.

The department has also given people a grace period.

"HMRC takes any disruption of service very seriously and to reflect this no-one who files electronically or by paper by midnight Friday 1 February will face a penalty," it said, adding that it "very much regrets any inconvenience this may have caused”.