Airlines have criticised the UK's air traffic control system after a second technical problem in two weeks caused major disruption to UK flights.

EasyJet said Monday's incident "once again calls into question the resilience" of the service, while Wizz Air said there was a "national confidence crisis" in National Air Traffic Services (Nats), which runs the UK's air traffic.

Nats said a "connectivity issue" at Prestwick was behind the disruption across Scotland, Northern Ireland and northern England - and had "nothing to do" with a separate software defect at Swanwick earlier this month.

Prime Minister Andy Burnham said further issues today "cause even greater concern" about the UK's air traffic control.

When asked by reporters whether he would look to fire the head of Nats, Burnham said "these are clearly serious issues and they need to be fully investigated".

He added that the transport secretary was taking the issues "extremely seriously" and initially it's a matter for her "to get to the bottom of... and why there has been a recurrence."

The underlying issue causing Monday's disruption has since been resolved, with Nats saying it was running at "full capacity" although officials warned of knock-on effects.

A spokesperson said they were now "focused on working with our customers to recover their residual delays and help get their operations back to normal".

More than 150 flights were cancelled at UK airports on Monday - including 140 departures and 137 arrivals, according to aviation analytics company Cirium.

Easyjet was the worst affected airline, with 48 of its 670 scheduled departures cancelled, while British Airways has seen 13 cancellations from its 513 scheduled departures.

The UK Civil Aviation Authority (CAA) said passengers who had flights disrupted were "unlikely" to be entitled to compensation.

It said the technical issue is "likely to be considered the result of 'extraordinary circumstances' under passenger rights rules", meaning that "although passengers should be looked after by airlines, they are unlikely to be entitled to compensation for delays or cancellations that were directly caused by the incident".

An independent review by the CAA into the resilience of the UK's air traffic control system is under way and the results will be published "within six months", it said.