What lying in state means and estimated queue times for people to view Queen's coffin

Her Majesty's coffin will be the first to lie in state in the Houses of Parliament since the Queen Mother's in 2002 after she died aged 101.

On that occasion an estimated 200,000 people filed past her coffin. However, even that large number is expected to be dwarfed when Elizabeth II's coffin is placed in Westminster later this week.

Whitehall chiefs organising the historic five-night vigil have estimated mourner numbers could be close be close to the one million who turned up to view Pope John Paul II when he lay in state in Rome in 2005.

What is lying in state?

Lying in state is a formal occasion where a coffin is on view so the public can pay their respects to the deceased before their funeral ceremony.

In the UK they are for the sovereign - the Head of State, the current or past Queen Consort and sometimes former Prime Ministers, and traditionally take place in Westminster Hall at the Houses of Parliament.

While lying in state, the Queen's coffin will rest on a raised platform in the middle of the hall. Each corner of the platform is guarded around the clock by units from the Sovereign's Bodyguard, Foot Guards or the Household Cavalry Mounted Regiment while members of the public file past the platform to pay their respects.

The tradition dates back to the 1600s when Stuart sovereigns lay in state for a number of days.

Notable occasions of people lying in state at Westminster Hall include:

• William Gladstone - 1898

• King Edward VII - 1910

• King George V - 1936

• King George VI - 1952

• Queen Mary - 1953

• Sir Winston Churchill - 1965

• Queen Elizabeth the Queen Mother - 2002

Another, unusual, lying in state took place in 1930 when the victims of the R101 airship disaster lay in Westminster Hall on October 10. The airship was one of two experimental rigid airships commissioned by the British government in the 1920s as a method of long-distance air travel, but caught fire in northern France, killing 48 out of 54 people on board.

When will the Queen lie in state?

People will be able to queue up from 5pm on Wednesday to see Her Majesty's coffin.

Westminster Hall will then be open continuously - meaning it will be open 24 hours a day - until 6.30am on Monday, September 19, the morning of Her Majesty's funeral.

How long will the queue be?

Even though Westminster Hall will be open for 24 hours a day for four whole days - as well as Wednesday evening and Monday morning - queues are expected to be very, very long.

'Insiders' have reportedly told The Sun people may have to wait up to 12 hours to view the coffin, in a queue stretching three miles.

The route of the queue is expected to stretch from Parliament's tourist entrance, Cromwell Green, down Millbank, past the Lords and Victoria Tower Gardens, across Lambeth Bridge and loops back north on the other side of the River Thames.

Full details of the route will be published at 10pm on Tuesday.

Organisers have warned those wishing to attend: "If you wish to attend the Lying-in-State, please note that there will be a queue, which is expected to be very long. You will need to stand for many hours, possibly overnight, with very little opportunity to sit down as the queue will be continuously moving."

With such long waits, portable loos and crowd control infrastructure like barriers and flooring have been now set up. People will not be allowed to camp and will be given numbered wristbands to indicate their place in the queue so they are able to leave and come back, it is understood.

Despite not being able to camp, the first person has already arrived to queue up. Vanessa Nathakumaran appeared at 12pm on Monday, more than 48 hours before the line was due to open.

The Rail Delivery Group has also warned those wanting to travel to London that stations are expected to be “extremely busy”.

The rail operator’s customer information director told the BBC people needed to plan carefully and allow plenty of time if planning to travel during the official mourning period.

Transport for London also warned that roads and public transport in central London will be very busy and has advised travellers to allow “plenty of extra time” for their journeys and to avoid driving where possible.

Infrastructure has been set up in preparation for miles of people queuing for the Queen's lying in state in Westminster Hall.

What can I take?

A strict bag policy will be in operation. Mourners can only being one small bag per person, and must not exceed 40cm x 30cm x 20cm. It must also have one simple opening or zip so people can move quickly through the security check.

Larger bags will have to be left in the bag drop facility, which you will be directed to, although officials are saying capacity is limited and there is no guarantee there will be space.

The following items are also not allowed into the security search point or Palace of Westminster:

• Bags larger than 40cm x 30cm x 20cm in size, bags or rucksacks with expandable compartments, bags or rucksacks with multiple pockets or complex openings, solid-sided bags, or bags on wheels

• Flasks or water bottles, except clear water bottles. Clear water bottles must be emptied of their contents before entering the security search point

• Food and liquid of any kind. Any food or liquids must be consumed in the queue or disposed of before entry

• Flowers or other tribute items (including candles, soft toys and photographs). These items cannot be taken into or left in the Palace of Westminster. Floral tributes only should be taken to the dedicated floral tribute area in Green Park

• Sharp items, including knives, Swiss Army knives, scissors, cutlery and screwdrivers

• Personal defence equipment or any object that could be used as a weapon and/or compromise public safety, including personal defence sprays

• Paint sprays, padlocks, chains, climbing gear, and dangerous or hazardous items

• Fireworks, smoke canisters, air-horns, flares, whistles, laser devices, and other items that could be used to cause a disturbance or noise

• Banners, placards, flags, advertising or marketing messages, and other similar items that could be used to cause a disturbance

• Coolers, hampers, sleeping bags, blankets, folding chairs and camping equipment

• Non-foldable pushchairs

• Any other items as directed by security staff or police

Prohibited items will be confiscated and will not be returned. Illegal items will be dealt with by the police.

Before entering the Palace of Westminster mourners will go through an airport-style security search point.

Dress code and behaviour

Those going to see the Queen's coffin are asked to "respect the dignity of this event and behave appropriately", which involves staying silent while inside the Palace of Westminster.

Stewards and police officers will patrol the queue. Antisocial or inappropriate behaviour (including queue-jumping, excessive consumption of alcohol or drunken behaviour) will not be tolerated.

People have been told to:

• Dress appropriately for the occasion to pay your respects at the Lying-in-State. Do not wear clothes with political or offensive slogans

• Turn mobile phones off or put them on silent before entering the security search area

• Dispose of litter using the litter bins provided

• Keep noise to a minimum, and respect people who live in residential areas near the queue

• Follow the instructions of stewards, marshals and the police at all times

Those attending must not:

• Film, photograph, or use mobile phones or other handheld devices in the security search area and the Palace of Westminster

• Bring or erect gazebos or tents

• Light barbecues or fires

• Attempt to queue on behalf of others or vice versa. Only those given wristbands at the end of the queue will be able to stay in the queue

• Leave personal items unattended in the queue. Bags or other items left unattended will be removed and may be destroyed