Dumbarton (UK Parliament constituency)  Dumbarton was a burgh constituency represented in the House of Commons of the Parliament of the United Kingdom from 1983 until 2005. It was largely absorbed into the new constituency of Dunbartonshire West, with Helensburgh joining Argyll and Bute. The Dumbarton constituency of the Scottish Parliament, which created in 1999 with the same boundaries, continues to exist. It consisted of the towns of Dumbarton, the Vale of Leven, and Helensburgh, plus a significant rural hinterland.