Collier's most notable break from Labour discipline came on assisted dying. In June 2025, he backed two additional safeguard clauses during the Report Stage of the Terminally Ill Adults (End of Life) Bill — including one specifically protecting devolution competencies in Scotland, Wales and Northern Ireland — when the Labour majority voted against them. He also voted against a Lib Dem motion on proportional representation in December 2024, rejecting a switch to single transferable vote despite Labour having won two-thirds of Commons seats with a third of votes cast. Both positions put him at odds with his party, though neither triggered wider rebellion.
Otherwise, Collier is a reliable Labour loyalist, voting with his party 99.3% of the time. His 81% voting participation sits a little below the Commons average. Stance data shows he is consistently aligned with progressive taxation and workers' rights, markedly more supportive of trade union rights than the average Labour MP, and notably more sceptical than colleagues on business-friendly measures and criminal justice reform. His 182 parliamentary contributions span economy and jobs, defence, local government and social care — a broad portfolio that reflects a generalist rather than a narrow specialist.
His membership of both the Petitions and Transport Committees fits a visible local campaigning pattern. News coverage highlights his lobbying of the Chancellor for A50 and A500 road upgrades, his advocacy role for the North Midlands Manufacturing Corridor, and a Westminster event to promote Burton regeneration ahead of a major investment conference. Recent local coverage across crime, transport and cost-of-living carries a neutral average sentiment. One legacy article about his predecessor Andrew Griffiths' misconduct appears in the data but relates to a different MP entirely.