In 2003, he was appointed as the council's Cabinet member for Education,[7] a post which he continued to hold for some months during 2005 while serving as Secretary General of the European Parliamentary Labour Party, in Brussels.

From there, he became Campaigns Manager for the National Society for the Prevention of Cruelty to Children,[5] and his last full-time job before his arrival in the House of Commons was as Director of Policy and Partnerships at the Royal College of Speech and Language Therapists.

[8] Smith was selected as Labour's prospective parliamentary candidate for Blaenau Gwent in 2007 and was elected as its Member of Parliament on 6 May 2010, defeating the incumbent Independent Dai Davies.

On his election success, Smith commented "The local population and the Blaenau Gwent Labour Party have shared values, and that's come through in this result tonight.

Speaking after the announcement, Smith said: "Today the voters of Blaenau Gwent shared my belief that our best hope to get our country moving again is a Labour government.

He praised the cultural and political heritage of the constituency, and promised to campaign strongly on improving public health, the prospects for young people, and economic growth.

He has highlighted a number of instances of the Ministry of Defence wasting tax payer's money, including changes to the requirements of the two Queen Elizabeth-class aircraft carriers that added billions of pounds to the cost of the contracts.

[31] Smith was the Labour Whip and Teller, reading the result to Parliament when Prime Minister May's Brexit deal fell to a record breaking defeat.

[32] Smith's campaigns have included criticising the interest rates that poor families are charged by the rent-to-own sector for buying household appliances.

[33] Since 2017, Smith has championed local steelworkers affected by the British Steel Pension Scheme scandal, including many across South Wales.

[38] Smith, who comes from a family of mineworkers, including his three uncles on his mother’s side [39] began campaigning on this issue around December 2017[40] and over the following seven years championed the cause, asking questions in the House of Commons, writing letters calling for action,[41] challenging Prime Minister Boris Johnson when a promise he made on this issue during the 2019 election was not fulfilled,[42] and helping to secure a Select Committee inquiry which supported the case for the money to be returned to mineworker pensioners.

[43] In its 2024 election manifesto The Labour Party pledged to “end the injustice of the Mineworkers' Pension Scheme”,[44] a promise that was fulfilled when, in her budget of October 2024, Chancellor Rachel Reeves MP announced that the Labour Government would be transferring the Mineworkers Pensions Scheme Investment Reserve Fund back to its members, translating to an immediate uplift of £29 a week on average for members.

[45] Reeves referred to Smith directly in her budget speech saying that she had “listened closely to [her] Honourable Friends for Easington, Doncaster Central, Blaenau Gwent, and Ayr, Carrick and Cumnock on this issue.”[46] Blaenau Gwent & Rhymney saw the highest number of mineworker pensioners receive the uplift in Wales with 1622 pension scheme members in the constituency.

I’m very pleased that they will now be justly rewarded.”[47] Smith ran his first London Marathon in 2018 for Hospice of the Valleys, a Blaenau Gwent charity who provide palliative care.

[48] Smith chairs the All Party Parliamentary Group on Parkrun and has promoted physical activity for improved public health and to help address obesity.

[53] Minutes of the meeting were provided to Welsh news service Nation.Cymru describing conflict with their MP among party members: "The motion was moved and seconded and the Chair opened the floor for discussion.

Comments made included members saying they didn't feel they could knock doors for the MP and that the CLP Constituency Labour Party needed a candidate that it could get behind in the election.

The article continues: A longstanding member of Blaenau Gwent CLP, who did not wish to be named, said: "People on the left in the local party have been unhappy with Nick Smith for a long time, but now he has opponents on the right who are against him too.