Parliament of the United Kingdom
The Parliament of the United Kingdom of Great Britain and Northern Ireland, commonly known internationally as the UK Parliament, British Parliament, or Westminster Parliament, and domestically simply as Parliament, is the supreme legislative body of the United Kingdom, and the British Overseas Territories. It alone possesses legislative supremacy and thereby ultimate power over all other political bodies in the UK and the overseas territories. Parliament is bicameral but has three parts, consisting of the Sovereign (the Queen-in-Parliament), the House of Lords, and the House of Commons (the primary chamber). The two houses meet in the Palace of Westminster in the City of Westminster, one of the inner boroughs of the capital city, London.
Separation of powers
A multi-party system parliament that must either form a minority executive or a coalition executive function as a perfectly good system of checks and balances even if it was never a stated goal for the introduction of multiparty system. The multiparty system came about in response to a public outcry of having too few parties and a general feeling of a lack of representation. For this reason you'll find very little on the topic of separation of powers or checks and balances in the works of Norwegian political sciences today.
The development of the British constitution, which is not a codified document, is based on this fusion in the person of the Monarch, who has a formal role to play in the legislature (Parliament, which is where legal and political sovereignty lies, is the Crown-in-Parliament, and is summoned and dissolved by the Sovereign who must give his or her Royal Assent to all Bills so that they become Acts), the executive (the Sovereign appoints all ministers of His/Her Majesty's Government, who govern in the name of the Crown) and the judiciary (the Sovereign, as the fount of justice, appoints all senior judges, and all public prosecutions are brought in his or her name).