Police have defended their tactics during a planned fuel protest on the M62 after deploying a device used to puncture tyres.
Drivers gathered at Ferrybridge Services at junction 33 of the motorway in West Yorkshire as part of a series of organised protests taking place across the country in response to spiralling fuel prices.
The motorists planned to drive in convoy along the motorway in a "go slow" designed to encourage the government to take action.
Similar protests were taking place across the motorway network, including the M180 near Immingham in Lincolnshire, the M4 between Bristol and south Wales and between Reading and London, the M5 and the M32.
But protestors were held up at Ferrybridge when a so-called stinger was laid down.
One of the demonstrators posted on Facebook: "West Yorkshire Police won't let anyone leave the Ferrybridge Services and have stingers out preventing the fuel price protest starting. So much for the lawful right to a peaceful protest."
In a series of tweets, West Yorkshire Police said officers were "negotiating with a small group of fuel price protestors at Ferrybridge motorway services regarding ways in which a peaceful, safe and lawful demonstration can be facilitated".
The force added that it acknowledged "the importance of lawful protests but will deal swiftly with any criminal offences".
"It is clear deliberate disruption of the network will inconvenience huge numbers of people, draw police resources away from other important work and potentially delay the response times of all emergency services," the force tweeted.
In a statement, a spokesperson said officers used "a number of tactics", including the stinger.
They said: "A single tyre deflation device was deployed in the early stages of the protest but not as a main method of traffic control. It was not used, no damage was caused to any vehicles, and it has been withdrawn."
In a later statement, Assistant Chief Constable Catherine Hankinson said the force had planned "extensively" for the action.
She said: "Officers have been conscious of the extremely emotive nature of high fuel prices and financial pain these costs are causing, but also of the significant impact a motorway protest would have on the region."
She said police needed to evaluate if a protest would disproportionately affect the rights of others.
"If it is felt that the actions of a small number will negatively impact the rights of the wider public, then the force is required to intervene and protect the majority.
"Police engaged with the small number of protestors who attended at Ferrybridge Services on Monday morning to explore possible ways in which they could peacefully demonstrate without negatively affecting the wider public.
"It was clear the proposed 'go slow' protest on the network would potentially have caused significant gridlock across the north of England.
"Officers took action to avoid the disruption and ensure the wider safety of protestors and road users."
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