Parliament is hit by IT issue with all computers on the estate down and MPs BLOCKED from checking their own e-mails

All computers on the parliamentary estate are down after a massive IT issue, it emerged today. 

MPs have been blocked from checking their own emails with annunciator screens across the state reading: 'There is an issue on the Parliamentary IT network and we are working to resolve it'. 

A spokesperson for Parliament said: 'The IT issue affecting the Parliamentary network has been identified and is being addressed urgently.

'The business of both chambers is unaffected'.

A source told MailOnline: 'The internet is working fine and as normal but MPs are saying they can't get into their e-mail accounts.'

It it understood that the IT outage is not believed to have been caused by a cyber-attack.