Bicycles lining railings outside the Avon Gorge Hotel were an indication of the Green Party masses in Bristol to launch their national General Election campaign.

Leaders, candidates and supporters marked what they called a “defining moment” in politics as they gathered against a backdrop of the Clifton Suspension Bridge on Thursday and issued a rallying call to young people, with promises to fight for free education and affordable housing.

Co-leader Caroline Lucas met with rapturous applause from the party faithful as she argued it is future generations who will bear the brunt of a wrecked environment and said there has never been a greater need for the Green Party.

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Education as a right rather than a privilege, votes for 16-year-olds, fighting for an end to the commercialisation of the NHS and a battle against a hard Brexit were top of the agenda for the party that has positioned itself as the “antidote to UKIP”.

The Greens were more prepared than most for Tuesday’s shock General Election announcement, having already named the candidates they will be fielding in Bristol.

With much of the party’s national hopes pinned on Molly Scott Cato who will stand against Labour’s Thangam Debbonaire in Bristol West, it was no surprise they chose the city to launch their General Election campaign.

Surrounded by supporters as young as two and from as far afield as Indonesia, Scott Cato, currently an MEP, called it the most important election in a generation as she pledged to fight for young people.

“We need votes at 16 now,” she said. “Last June, we saw a horrendous example of not giving votes to 16 and 17-year-olds with the Brexit referendum. This was a decision that will impact 16-year-olds for the rest of their lives and they had to sit back and watch.”

She argued the plight faced by young people, including crippling student debt and lack of affordable homes, is reflected in the wider population, adding that this is the party’s time to shine as she expressed confidence in her chances of winning and securing a place in the history books.

Lucas, the party’s only current MP, said: “Winning Bristol West is just within our grasp. It’s so important that people have chance to stand up for a genuinely progressive party.”

She added that young people have been betrayed in many ways, with the lack of affordable housing just one example of this.

Co-leader Jonathan Bartley spoke of a feeling of hope as he addressed the crowd. “This is a defining moment,” he said. “It’s not about the next five years, it’s about the next 50 years.

“We have got a Government that has listened to UKIP. UKIP has said jump and the government has said how high. We are the antidote to UKIP.”

The treasurer for the Indonesian Green Party, Dian Abraham, was among the supporters who made it to Bristol and he said global backing for the movement to preserve our environment and challenge the political elite is ever growing.

Debbonaire gained 36 per cent of the vote to win the Bristol West seat in the 2015 General Election, beating Green candidate Darren Hall, who secured 27 per cent, while former Lib Dem MP Stephen Williams received just 19 per cent of the votes.

Hall is currently the Green candidate competing against Williams in the metro mayor elections.

On her Westminster election chances, Scott Cato told Bristol24/7: “This is our time. We are determined to increase our parliamentary representation. It was an extraordinary result last time. I think we have broken the barrier. When you are on 27 per cent, we are as likely to win as anyone else.

“Bristol has always been a green city and this is the time for us, I am confident.”

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