Theresa May has confirmed she will be supporting the "remain" campaign to stay in the EU.
The Home Secretary said the EU was "far from perfect" but that it was "in the national interest" for Britain to remain part of it.
She said: “This deal includes important reforms to prevent the abuse of free movement. It means we keep control of our right to decide which criminal justice measures we participate in. It strengthens our ability to deport dangerous foreign criminals. And while European countries must work together to tackle terrorism, it makes clear that our national security is ultimately our responsibility, not Europe’s.
“The EU is far from perfect, and no one should be in any doubt that this deal must be part of an ongoing process of change and reform – crucial if it is to succeed in a changing world.
"But in my view - for reasons of security, protection against crime and terrorism, trade with Europe, and access to markets around the world - it is in the national interest to remain a member of the European Union."
David Cameron has warned that Britain has "100 days to secure our future", as a poll suggests the final result hangs in the balance.
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Britain's car industry is an economic success story, and with uncertainty over the impact of Brexit, it wants to stay put.