To what extent is Britain a liberal democracy?

To what extent is Britain a liberal democracy?
The balance of evidence would suggest that Britain conforms very well to the principles of a liberal democracy. Whilst there are always points of evidence that could be used against this view, it is my view that these are outweighed by the positive evidence and examples.
When determining whether the country is a liberal democracy, one has to begin by discussing and defining the features of a liberal democracy. A liberal democracy is defined as one where there are free and fair elections, where the right and liberties of citizens are taken into account and protected, where the government is clearly accountable to people and the powers of government are controlled and limited by law and conform to a written constitution. In addition, a liberal democracy is a tolerant democracy where a variety of opinions, cultures and lifestyles are accepted and accommodated, as long as they do not threaten the security and peace of the state. In a liberal democracy, information is freely available to its citizens and the political parties all accept the legitimacy of the election process and all commit to peaceful and orderly transfers of power.
Those that argue that Britain is not a liberal democracy often argue that it cannot be because it does not have a written constitution. This means that there are no fundamental laws to safeguard against attempts by government to take more power than they should. They often argue that there is clear evidence from recent terrorist and security threats that the UK culture is no longer tolerant but is becoming overly intolerant of cultures and religions that it perceives to be a threat. They would also argue that under the umbrella or indeed excuse of national security, information is increasingly kept from the public and this in turn causes damage to the public interest. They would also argue that the UK ‘first past the post’ election system is inherently unfair, as it is very rare that a