BRUSSELS (Reuters) - Britain is free to diverge from European Union rules after Dec. 31, but that divergence must be reasonable if it wants zero-tariff and zero-quota access to the bloc’s 450 million consumers and 22 million companies, the EU’s Brexit negotiator said. “We are absolutely determined to reach a fair deal with the UK. We will do everything that we can, but not at any price,” Michel Barnier told a news conference after EU leaders discussed the impasse in Brexit negotiations. My negotiation team and I will continue intensive discussions over the coming weeks,” he said. “Our position has been crystal clear... If you want access to our market of 450 million people, there must be a level playing field.”