Explain the what is meant by the 'Separation of Powers' and how the idea pertains to the British Political System

The separation of powers is a concept first articulated by Montesquieu in his book 'The Spirit of the Laws'. In the book Montesquieu puts forward the idea that if the executive, legislative and judicial functions or powers are vested in one person or one body of persons, there will be only tyranny and the oppression of freedom and civil liberties. Therefore the three branches must remain separate to ensure that such autocracy cannot occur.

Britain, unlike other countries such as the United States, has no clear separation of powers. Walter Baghot famously wrote that the efficient secret of the British Constitution, was the near complete fusion of the executive and legisltave powers, this fact resulting from members of the executive also sitting as MPs in Parliament (the legislature). The judiciary in Britain however has remained separate, with many critics arguing that judges in fact provide the most stringent checks on both the legislative and executive branches in our current modern constituional settlement.