Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Candidate | Party | Constituency | Year | Days |
| --- | --- | --- | --- | --- |
| Alfred Dobbs | Labour | Smethwick | 1945 | 1 1 |
| John Sunderland | Labour | Preston | 1945 | 122 1 |
| John Whittaker | Labour | Heywood and Radcliffe | 1945 | 137 1 |
| Philip Clarke | Sinn Féin | Fermanagh and South Tyrone | 1955 | 152 3x |
| Thomas Mitchell | Sinn Féin | Mid-Ulster | 1955 | 152 3x |
| Harry West | Ulster Unionist | Fermanagh and South Tyrone | February 1974 | 224 2 |
| Michael Ancram | Conservative | Berwick and East Lothian | February 1974 | 224 2a |
| Barry Henderson | Conservative | East Dunbartonshire | February 1974 | 224 2a |
| Paul Tyler | Liberal | Bodmin | February 1974 | 224 2a |
| Michael Winstanley | Liberal | Hazel Grove | February 1974 | 224 2b |
| James Godfrey MacManaway | Ulster Unionist | Belfast West | 1950 | 238 3 |
| Judith Chaplin | Conservative | Newbury | 1992 | 316 1 |
| Peter Law | Independent | Blaenau Gwent | 2005 | 355 1 |
Question:
In 1955 which party did Thomas Mitchell belong to?
Answer:
Sinn Féin