Natalie Bennett, the leader of the Green Party, claims that European laws are working well for Britain, and that it'd be wrong to leave the EU.
"We believe we need to work together, jointly on the problems we face," she told Paul Ross. "Things like workers rights. We need to set standards right across Europe, things like air pollution, water pollution."
"We celebrate free movement of people in the EU, we think that enriches all of our lives.
"We have these standards that are being set by the EU. All of these are collective democratic agreements across Europe that we should meet standards, and they've improved the lives of people in Britain."
Bennett warns of the huge task ahead if we were to choose to leave.
"What we'd have to do is write a huge list of all of those workers rights, all of those environmental protections that come to us through the EU. Some of them we would lose with immediate danger. At the moment they've got legal protection. That protection would disappear."
She refuted claims that immigrants negatively impact the economy.
"We have low wages because we have an economy dominated by big multi-national companies, rather than independent medium sized businesses.
"People from all round the world... are paying their taxes in to help fund the NHS. The people who aren't paying their taxes, the people to blame for the fact that the NHS is underfunded, is the government for not putting enough money in.
"If we're going to stand up to the Googles, the Amazons, all of these kinds of companies, we need to be as big and strong as possible, and we're much better as the people of Europe standing up against them."
The Green Party is calling for a change in the way politics is conducted.
"What we need to do is not change the system, not get out of Europe. What we need to do is change our politics.
"Elect different politicians, elects the kind of politics that says we have to live within our environmental limits, while ensuring that no one has to worry about putting food on the table and keeping a roof over their heads."