[3] The most common causes of Operation Stack are severe weather that either cancels or restricts ferry services, industrial action at the French ports of Calais, Dunkirk, and Boulogne, and electrical failures in the Channel Tunnel.

[11] Operation Stack was first introduced in February 1988, because of a strike called by the National Union of Seamen in Folkestone Docks, which was then an important ferry terminal, that began on 31 January.

[13] The following year, Michael Howard asked Secretary of State for the Environment, Transport and the Regions John Prescott about alternative methods to Operation Stack.

Prescott replied that he would investigate matters but defended the status quo, saying "Management schemes can make traffic flows much better, and they are almost inevitable in difficult circumstances.

"[14] In early 2005, Kent Police implemented Operation Stack several times within a few weeks due to bad weather (snow), a strike and a damaged berth in Calais, which limited the number of ferries which could cross the channel.

[15] At the end of January 2007, local Members of Parliament Damian Green of Ashford and Stephen Ladyman of Thanet were involved in a debate covering Operation Stack in the House of Commons.

The MEP for South East England, Richard Ashworth, and the leader of Kent County Council, Paul Carter, urged French president Nicolas Sarkozy to step in and resolve the dispute because of the resulting difficulties.

[24] Over 4,600 HGVs were eventually cleared from the M20 by 4 July,[24] however soon afterwards Phase 2 was implemented again for Eurotunnel freight traffic, due to over 150 migrants storming the Calais tunnel portal.

Damian Collins, MP for Folkestone and Hythe complained the problem was too large for Kent County Council to deal with and met with the Home Secretary, Theresa May for discussion.

National Highways says, "the Operation Brock contraflow system is designed to keep traffic on the M20 and other roads in Kent moving when there is disruption to travel across the English Channel".