Member of the Senedd for Neath

Following the announcement by Gwenda Thomas, the then-Assembly Member for Neath, that she was planning to stand down at the 2016 National Assembly for Wales election, he was selected to stand as the Labour and Co-operative candidate in Neath constituency in October 2015, following a twinned selection process with Gower constituency.^[8]

He was until his selection as the candidate for Neath a trustee and secretary of the social justice charity the Bevan Foundation.^[9]

He was elected to the Senedd in May 2016 and was one of the first out gay MSs elected.^[10] In November 2017, he was nominated to be the Counsel General for Wales. Before his appointment to government, he sat on the Economy, Skills and Infrastructure committee, Culture, Welsh Language and Communications committee and the External Affairs committee and was the chair of the Co-operative group of AMs.^[11]

Counsel General for Wales (2017–2021), Minister for European Transition (2018–2021)

In November 2017, First Minister of Wales Carwyn Jones undertook a Welsh Government reshuffle.^[12] Miles was nominated to the cabinet-level role of Counsel General.^[13]

In March 2018, he introduced draft legislation that would create a codified statute book of Welsh law, which would make Wales the first of the home nations to organise its laws in this way. The statute book would be designed to improve accessibility to Welsh Law for both lawyers and the general population.^[14]

In 2019, he led for the Welsh Government in taking legislation through the Senedd which for the first time introduced votes for 16 year olds in Senedd elections.^[15] The subsequent 2021 Senedd election was the first election that 16 year olds in Wales could vote.^[16]

In his role as Counsel General he announced in 2019 his decision that the Welsh Government would join the case brought by Gina Miller against the UK Conservative Government in the Supreme Court, arguing that the Conservative government acted unconstitutionally in proroguing Parliament and denying the Senedd the opportunity to influence the course of Brexit.^[17] The case was successful and the Supreme Court ruled that Boris Johnson had acted unlawfully. ^[18]

In July 2020 he issued a joint statement with Jane Hutt, equalities minister on the human rights of the trans community and confirming the Welsh Government’s support for equal rights for trans people. ^[19]

He brought another legal case against the Conservative Government in 2021 over the Internal Market Act which gave the UK Government sweeping new powers in devolved areas, arguing that the UK Government was “stealing powers from devolved governments” and that the Act was “an attack on democracy and an affront to the people of Wales”.^[20]

As Minister for European Transition he led the co-ordination of the Welsh Government’s activities to prepare Wales for the UK’s departure from the European Union, for was also responsible for liaising with the UK Government over Britain’s negotiations to leave the EU and he represented the Welsh Government in negotiations with the UK Government and other devolved governments for the Intergovernmental Relations Review, to strengthen Wales’ voice in intergovernmental relations.^[21] In May 2019 he argued for a change in the Welsh Government’s policy so that it would support another Brexit referendum, and that the UK Government had failed to deliver a deal with the EU based on promises made in the first referendum. ^[22]

During the Covid pandemic he was also tasked with post-Covid planning. He convened a series of experts to guide Wales’ longer-term planning which included Gordon Brown^[23] and launched a national conversation through the “Our Future Wales” campaign where the public could email proposals to be considered by the government, based on their Covid experiences.^[24] This led to the publication of a post-Covid priorities plan in October 2020.^[25]

2024 leadership election

In December 2023, following the resignation of Mark Drakeford, Miles stood (along with Vaughan Gething) for the election to succeed him as both party leader and therefore First Minister of Wales.^[26]