The suspected letter bomb that caused Brighton city centre to be evacuated was the work of “amateurs” according to an MP.

Hundreds of people had to leave businesses and buildings on Thursday after the suspicious package was discovered at the army recruitment centre in Queen's Road.

It was part of a national terror plot that involved letters sent to seven locations in the south east, and has been linked to Irish Republican terrorists.

MP Andre Mercer, a former Army colonel who commanded UK troops in Northern Ireland, told the Mail on Sunday forensic evidence suggested the bombers lacked experience.

He said: “I understand that they were amateurish in their construction.

“The devices are thought to have been sent by members of the Real IRA, however there is currently a feud inside this organisation about whether to mount a campaign in mainland Britain.”

The army recruitment centre has remained open since the scare but is still on high alert.

Police said two if the packages were posted in Dublin and a third package has been traced to an area close to the border with Northern Ireland, but is unclear if the Brighton package is among these.

More detail is likely to emerge today about the suspected letter bomb as counter terrorist units continue to examine the package.

The bomb scare saw a large section of Queen's Road evacuated and a navy bomb disposal unit including robotic device deployed on Thursday lunchtime, bringing the city centre to a halt.