Labour Leader Jeremy Corbyn says he is 'disturbed' that Nissan could cease investment in the region.
This week Nissan announced it will want the UK Government to pledge compensation for any extra costs as a result of Brexit before it invests in its Sunderland plant.
Nissan currently builds around one in three of all of Britain's total automotive output at Sunderland.
Mr Corbyn, who was in the region this weekend to mark the 80th anniversary of the Jarrow march, said: "I am disturbed that Nissan have said they are going to pause investment, because clearly the Nissan plant is incredibly efficient and produces good quality cars with the vast majority going to the European market.
"The government has to step up the pace of negotiations to ensure that we do have market access to Europe in the future."
Mr Corbyn said he has already had discussions with socialist colleagues all across Europe about maintaining access to Europe for manufacturing industries.
When asked at the Paris Motor Show what factors the company would consider in deciding where to build any future model, Nissan Chief Executive Carlos Ghosn told reporters: "If I need to make an investment in the next few months and I can't wait until the end of Brexit, then I have to make a deal with the UK government.
"You can have commitments of compensation in case you have something negative. If there are tax barriers being established on cars, you have to have a commitment for carmakers who export to Europe that there is some kind of compensation."
Mr Ghosn told the BBC the Sunderland plant would lose competitiveness if Britain was left dealing with the EU under World Trade Organisation rules - rather than as part of the Single Market.
While in the region Mr Corbyn also said he is challenging the proposed boundary commission changes, which could see the region lose three Labour MPs, because they do not take into account two million new voters.