Home Office engineers have been working "through the night" to correct a glitch that saw mass disruption at airports and sea ports across the UK.
The systems glitch meant that border staff had to manually input passport details for arrivals into the UK, as document scanners were malfunctioning.
It has been further reported that the glitch also affected self-service passport gates, with London Gatwick in particular being beset by problems.
Immigration Minister James Brokenshire today stated that "the current situation is much improved and we are doing our best to keep waiting times to a minimum during this morning's busy period".
He said the government apologises for delays to travel, but that "security must remain our priority at all times".
Michael Allen, VP of APM at IT services firm Compuware, was at London Heathrow yesterday night.
"It was crazy," he said. "Quite simply it's not acceptable for IT problems to cause this level of pain. IT systems have become more complex in recent years and it seems this complexity is increasingly leading to problems like this. IT teams should have the processes, techniques and tools in place to proactively avoid these problems and be equipped to deal with unexpected IT problems before they impact their users.
"They should be able to see potential problems bubbling up and deal with them before it gets to the point it did last night where thousands of us were moving at a foot a minute in the passport control queue," Allen continued.
"My guess is that as their IT systems have become more complex over the last decade, their ability to prevent or deal with these types of problems has decreased," he added.
Allen believes that modern IT systems need to be equipped with "sufficient intelligence-gathering power so while your systems might not yet be able to heal themselves automatically quite yet, you are given sufficient notice and insights when things start to go bad so you know before your users do".