Parliament is sovereign. This is demonstrated by Dicey's three test of parliament sovereignty. As parliament can make and unmake any law for example the Treaty of union with Ireland 1800. The second and third part of the test being that parliament cannot bind it successes (Ireland act 1949) and no one can question any law that parliament makes (Railway board v. Pickin)

The House of Lords has to obey parliament. This was established by the 1911 act and the 1949 parliament act. Which curtailed the right of the House of Lords to block a bill that parliament had passed from becoming law. Reaffirming that Parliament is the most powerful organ within the state.

As an elected body parliaments duty is to represent is constituents by it members. Due to the nature of politics most MP's are affiliated with different political parties. They are under an obligation to toe the party line or risk being expelled from the party. MP's do enjoy special rights to enable them to their job properly. Such as parliamentary privilege where they cannot be held liable for anything that is said within the House of Commons. This can be demonstrated by the Balfour case where a nurse claimed slander when it was reported that she had failed to do her job properly. The courts refused to hear the case as it was covered by parliamentary privilege. This is an important privilege as it gives MP's complete freedom to express their views. If an MP goes to far as the case of Revelin where the house of commons voted that information distributed to MP's outside the house did not fall in the category as the material was personal in nature and did not concern the house or its business.

Parliament has delegated some it powers to different bodies. For parliament to join the EC it had to pass the European community's act to allow the EC to legislate over the UK. This can be seen as an erosion of parliament sovereignty. As it effectively gives permission to the EC to pass legislation that the UK must comply with. It is possible for Parliament to appeal this act and so established itself as the supreme body. As an active member both in the commission and in the European parliament with local elections being held it can be seen that the EU will take a more dominate role in UK Law making.

This transition of powers has been seen in cases such as Factortame where a declaration of incompatibility had to be issued as UK law was incompatible with EU law . The courts must give effect to EU provisions. This has also been seen in Francovich where the offending member state had to pay compensation to an individual as it was not in compliance with EU law.
It would appear that parliament is kept in check by the balance of powers. Quite often when ministers over step their powers in secondary legislation. For example ex parte brigades the court ruled that a minster had to implement a pension scheme within the defined time. It was not at liberty not to implement it just because the time period had lapsed in the legislation.

There are also a number prerogative powers excised by the prime minister in the name of the crown. Such as the act to declare war. A good example of this is the gulf war where it was unpopular but the PM had the authority to sanction such activity even though it was unpopular with the electorate. There was no vote of confidence held in parliament to question this action although there were formal demonstrations.
As the UK operates a first past the fence voting system, which has been criticized for not being truly representative (Jenkins report). It appears that has not been any further legislation to change this. This could be argued that it suits the large dominant parties of British politics. SDP would do much better under such a system.

In conclusion Parliament is not unrepresentative as it still holds the keys to power and it could appeal any of the acts it has made. In theory the power is loaned to different organisation so long as it is in accordance with parliaments wishes. However there are the first signs of erosion of representation as EU Law becomes more dominant. If the UK government wanted to strengthen representation it would need to start with the electoral role system. The counter arguments to this are that it only makes a complicated process more complicated but that is true representation.