In 1868 Matthews was elected Member of Parliament for Dungarvan. He described himself as an 'Independent Liberal and Conservative'. He was a Roman Catholic and supported the disestablishment of the Church of Ireland and was vaguely sympathetic to the Home Rule movement, but this could not prevent his defeat by a Home Rule candidate in the 1874 General Election. He then revised his views on politics and revived his political career as a Conservative in Britain, but in the circumstances of the struggle over Gladstone's Home Rule Bill, his previous position meant that he was distrusted by strong Unionists.