or one year by the Parliament Act 1949 ). Since the passage of these Acts, the House of Commons has become the dominant branch of Parliament, both in theory and in practice. In 1918, women over 30 were given the right to vote, quickly followed by the passage of a law enabling women to be eligible for election as Members of Parliament at the younger age of 21. The only woman to be elected that year was an Irish Sinn Fin candidate, Constance Markievicz , who therefore became the first woman MP. However, due to Sinn Fin's policy of abstention from Westminster, she never took her seat. [3] Since the 17th century, MPs had been unpaid. Most of the men elected to the Commons had private incomes, while a few relied on financial support from a wealthy patron. Early Labour MPs were often provided with a salary by a trade union, but this was declared illegal by a House of Lords judgment of 1909. Consequently a resolution was passed in the House of Commons in 1911 introducing salaries for MPs. Government ministers had always been paid. Since 1950 each Member of Parliament represents a single constituency. There remains a technical distinction between county constituencies and borough constituencies , but the only effect of this difference is the amount of money candidates are allowed to spend during campaigns. The boundaries of the constituencies are determined by four permanent and independent Boundary Commissions , one each for England, Wales, Scotland, and Northern