Under Secretary at Department for Communities and Local Government (DCLG). As communities minister, his responsibilities included community cohesion, race relations, localism and community rights, empty homes, housing standards, building regulations, neighbourhood planning, climate change and sustainable development. In March 2014, Williams published the Government's proposals following the housing standards review, which recommended a rationalisation of government, local authority and industry housing standards into a national set. As Minister for Communities, Williams also announced new funding for promotion of the Cornish language and gave recognition to the people of Cornwall as a national minority on the same basis as the other celtic people of the British Isles. In 2017, it emerged that Williams had responded to 2014 concerns from the All-Party Parliamentary Fire Safety and Rescue Group about the fire safety of Britain's tower blocks, especially the absence of sprinklers in many of these, by saying, "I have neither seen nor heard anything that would suggest that consideration of these specific potential changes is urgent and I am not willing to disrupt the work of this department by asking that these matters are brought forward." The correspondence was leaked to the BBC after the Grenfell Tower fire. In the 2015 United Kingdom general election, Williams lost his seat to Labour Party candidate Thangam Debbonaire. He came third with 18.8% of the vote. Before the election, he said he was concerned about losing support amongst students for abstaining on the vote to increase tuition fees to £9,000 a year. Post-Parliamentary career He was selected as the Liberal Democrat candidate in the 2017 West of England mayoral election, in which he came third with 20.2% of the vote. In the same year, he stood for his former seat of Bristol West, saying that the Liberal Democrat policy about UK membership of the European Union would mean he could win the seat back. He came fourth with 7.3% of the vote. In the 2019 European Parliament election, he was selected as the third candidate on the Liberal Democrat list for South West England. The list received 23.2% of the vote, with the two candidates ahead of him being elected. He was the Liberal Democrat candidate again in the 2021 West of England mayoral election. He came in fourth place, with 16.3% of the vote. Williams was also selected as the Liberal Democrat candidate in the 2023 by-election in the Hotwells and Harbourside Bristol City