A stretch of motorway remains closed in the search for an escaped prisoner held on terrorism charges with 150 police officers and staff involved in the manhunt.

Former soldier Daniel Abed Khalife, 21, broke out of Wandsworth prison in south-west London on Wednesday morning by clinging onto a delivery van.

A search led by the Metropolitan Police has been ongoing ever since - but so far there have been no confirmed sightings of the prisoner.

He was declared missing at 7.50am and by 8.37am, officers had tracked down the delivery van Khalife utilised, searched it and spoke with its driver.

Commander Dominic Murphy, who leads the investigation, said: “Over 150 officers and staff have been working around the clock on apprehending Khalife.

"We have issued a nationwide alert that has resulted in increased security at our ports and borders, however currently there have not been any confirmed sightings.

“I recognise and am fully aware of the impact these measures are having on the public.

“We are working to ensure as minimal disruption as possible.

“It is crucial for the public to help us with this search and to call us immediately if they have any information on the whereabouts of Khalife.”

While he is not assessed to pose a threat to the wider public we advise anyone who seems him not to approach him and instead call 999 immediately.

To allow for extra security checks, police have closed a stretch of the M20 between Junction 8 for Leeds Castle and Junction 9 for Ashford.

Bosses say the closure will allow freight bound for the continent to queue on the empty section of motorway "in order to keep any disruption to Kent’s wider road network to a minimum".

All EU-bound freight must use the M20 while all other traffic must follow the signed diversions, with drivers currently being directed to the A20.

Temporary chief superintendent Simon Alland said: "The closure of the M20 is an emergency measure that is only used following consultation with our partners in the Kent Resilience Forum (KRF) and after a thorough assessment of issues including public safety and traffic volumes.

"The KRF will continue to monitor the situation closely in order to restore the motorway to its full capacity as soon as possible."

Drivers may see stretches of the motorway clear from time to time as groups of freight are moved down the queue in stages when space becomes available.

Non-freight traffic currently being diverted onto the A20 is able to rejoin the M20 in front of the queue at Junction 9.

It comes as extra checks have begun at the Port of Dover, which has released a statement warning delays are to be expected.

“Due to a police matter, there are currently enhanced checks on outbound traffic at the Port of Dover and other portals within the UK,” said the message.

“Please be advised this is currently resulting in some delays at the port.

“However, our standard travel guidance remains unchanged and we will keep passengers updated if they can expect any alteration to their journey.”

Knock-on delays are being experienced around the motorway and major road network in the county.

Queues have been tailing back to junction 7 with problems heading along the A249 Detling Hill towards the M2.

Traffic leaving junction 8 to head along the A20 diversion has also been extremely heavy near Leeds Castle.

Khalife is accused of planting a fake bomb and gathering information that might be useful to terrorists or enemies of the UK, but denies all charges.

He went missing in his cook’s uniform from HMP Wandsworth, which is a category B prison - the second highest level of security.

The prisoner was on remand awaiting a November 13 trial at Woolwich Crown Court in relation to terrorism and Official Secrets Act offences.

Khalife was last seen wearing a white t-shirt, red and white chequered trousers and brown steel toe cap boots.

Met Police have issued an urgent appeal to the public to help trace the 21-year-old, who is described as being around 6ft 2ins tall, of slim build, with short brown hair.

Having links to Kingston, officers believe he likely remains in the London area, but may have travelled further afield by now and an all ports alert has been issued across the country sparking delays at UK airports and other ports including Dover and the Channel Tunnel in Folkestone.

Police also confirmed an alert was issued by the Counter Terrorism Command on Wednesday in relation to Khalife through established operational briefing channels to relevant UK police and law enforcements agencies, including those at UK ports and borders.

Restrictions have only just been lifted from the M20 between Junctions 8 and 9 following months of disruption.

In a statement, bosses at National Highways said: “At this stage, Kent Police is unable to advise any times for the reopening of the M20”.

At midday on Thursday, and shortly after the M20 was closed at Junction 8, queues stretched back for about three miles approaching the closure, with an estimated delay of about an hour.

Andrew Rintoul - National Highways south east regional operations manager - said: "We are starting to see traffic building towards the closure at Junction 8 on the coastbound M20, and I would urge anyone travelling in the area to allow extra time to complete their journey.

"Along with our partners in the KRF we have carefully planned contingency plans to help keep Kent moving when we do encounter delays at the ports.

"We understand the inconvenience this can cause and appreciate the patience of road users. The situation will continue to be closely monitored over the remainder of today and we will keep you updated on any changes or the removal of the closure."

Officers have traced the route of the van after it left Wandsworth Prison and are appealing to anyone who might have seen the vehicle on this route to get in touch.

The van left HMP Wandsworth at 07:32 taking a right turn out of gates onto Heathfield Road. It then turned left onto Magdalen Road. The van then turned left onto Trinity Road (A214) up to the Wandsworth Roundabout. It took the first exit onto Swandon Way (A217).

It then turned left onto Old York Road (past Wandsworth Town station) then left onto Fairfield Street, right onto Wandsworth High Street (A3) staying straight ahead onto West Hill and then on to Upper Richmond Road (A205).

Khalife’s previous military experience may mean he may be more aware of efforts to apprehend him.

If seen, the public are advised not to approach Khalife and to call 999 immediately, quoting reference CAD 1631/06SEP23.