Dozens of protesters against the expansion of Luton Airport went ahead with a march on Sunday despite being banned from land near the airport.
The protesters were banned from marching on airport land
The group Campaign Against Runway Expansion took part in a peaceful walk from Breachwood Green to the airport.
Police had served protesters with a Section 12 order banning them from their planned route.
The group says plans to build a longer runway would lead to more noise and traffic congestion.
The airport agrees better roads would be needed, but says noise problems should ease as quieter planes are developed.
MP for Hitchin and Harpenden, Peter Lilley, who joined the marchers, said the expansion was the biggest issue affecting this part of Hertfordshire.
"If expansion goes ahead, it will be an extra 25m people being disgorged onto the roads of Hertfordshire, greater pressure for development, a jumbo jet a minute landing and taking off on an airport which as not been designed and cannot take that sort of usage."
He said modest growth would be acceptable to most people but the "quantum leap" proposed to an airport the size of Gatwick was just too much.