The Metropolitan Police said 54 protesters were arrested on suspicion of wilful obstruction of the highway on Tuesday during a fourth day of demonstrations in Westminster.
They remain in custody at various police stations in the capital.
Just Stop Oil said 60 supporters of its group “disrupted traffic in Westminster today … in a row to demand an end to new oil and gas”.
It added that they chanted “no new oil” outside Downing Street before marching in the road towards Parliament Square, where they blocked the road by sitting on the ground while others glued themselves to it.
The demonstration was held in response to plans by the North Sea Transition Authority (NSTA), the body that represents the UK’s offshore energy sector, which is hoping to launch a further round of oil and gas licensing in October.
UK Business and Energy Secretary Jacob Rees-Mogg has given the move the green light, stating that “in light of Putin’s illegal invasion of Ukraine and weaponisation of energy, strengthening our energy security is an absolute priority”.
Environmental activists meanwhile are opposed to the plans, with some considering legal action.
One supporter of Just Stop Oil, Alan Woods, 58, said: “I’m a supporter of Just Stop Oil because as a business owner I won’t have business left unless we pressure our Government to stop all new oil and gas, invest in renewables and roll out insulation.
“The solution to the energy crisis and the climate crisis are the same – we’re at a crossroads. The Government must make the right choice.
“As a business owner of over 40 years I’ve seen a lot of challenges, but the climate and energy crisis is the most important issue of our time; that’s why I have to be here when I should be back in Wigan running my business.”
Just Stop Oil has vowed to continue its campaign until the Government meets its demands, which is for no more new oil and gas projects to be approved in the UK.
“We will not stand by while everything we know and love is wilfully destroyed. We do this because it is the right thing to do and so we have a duty, a responsibility to continue,” a statement from the group said.
A spokesperson from the Met said: “From 11:00hrs protesters began to assemble at Richmond Terrace before moving on to Parliament Square.
“At about 12:10hrs, protesters blocked traffic routes into Parliament Square, five of whom glued themselves to the ground.
“Officers have engaged with protesters and some left the scene.
“Officers arrested 54 protestors on suspicion of wilful obstruction of the highway. They have been taken into custody at various London police stations where they remain.
“By approximately 14.30hrs, officers had re-opened access routes to Parliament Square.”
The force previously stated 31 people were arrested in central London on Sunday.
The Government has been contacted for comment.