Winner of Chesham & Amersham by-election Sarah Green takes oath in Welsh as she is sworn in at House of Commons

Sarah Green taking her oath in Welsh.

A newly elected MP for a constituency in England spoke in Welsh as she was sworn in at the House of Commons.

Sarah Green, MP for Chesham & Amersham, won her seat after a by-election triggered by the death of veteran Tory MP Dame Cheryl Gillan.

In a surprise victory, Ms Green overturned a Conservative majority of more than 16,000 to win by 8,028 votes. 

Sarah Green won her seat in a surprise victory in the Chesham & Amersham by-election. Credit: PA

On Monday, the Liberal Democrat politician was welcomed by the party's Parliament leader Sir Ed Davey as she attended the House of Commons for the first time as an MP.

When swearing in, the Corwen-born politician and fluent Welsh speaker chose to speak in her native language.

Members of both Houses of Parliament are required by law to take an oath of allegiance to the Crown.

MPs cannot take their seat, speak in debates, vote or receive a salary until taking the oath or affirmation.

Politicians are able to take this oath in English, Welsh, Scottish Gaelic and Cornish.

Rachael Hamilton was the first politician in the Scottish Parliament to take her oath in Welsh Credit: Scottish Parliament TV

In May, a politician in the Scottish parliament became the first person there to take the oath in Welsh.

Scottish Conservative Party politician Rachael Hamilton, who is originally from Brecon, spoke in her native language as she pledged her allegiance to the Queen.