Labour will come under pressure to support inflation-matching pay increases, joining picket lines, renationalisation and the return of Jeremy Corbyn as a party candidate, in a crucial annual conference for Keir Starmer. The Labour leader will use next weekend’s conference to set out key dividing lines after the government’s mini-budget on Friday, with announcements on tax cuts, bankers’ bonuses and borrowing set to dominate the political debate for months to come. However, the party will also be confronted with some of the issues that have caused divisions among the membership and MPs over the summer. Among them will be numerous demands from local parties to make it clear that Labour MPs can join picket lines, an issue likely to flare up again this autumn as more public sector workers contemplate strike action. Starmer caused anger among MPs when he sacked frontbencher Sam Tarry after he joined a picket line of rail workers and backed pay increases that matched inflation. The party said he was fired for backing policies that had not been agreed by the leadership rather than his presence alongside striking workers. Labour frontbenchers had earlier been instructed not to join picket lines. Several motions backed by the country’s most powerful unions have been submitted to the conference underlining the duty of MPs to support strikers. The unions hold significant power over what is discussed at the conference. The issue causing the leadership most concern, however, is the demand from delegates for the party to back pay increases that match inflation – a headline policy for many unions. Starmer has not backed public sector pay increases in line with inflation, currently running at almost 10%, despite serious pressure. Another clash is looming over renationalisation of the water industry, Royal Mail, the railways and large parts of the energy industry. One motion on the issue demands renationalisation “so that Britons are no longer ripped off and workers get a fair deal”. It comes after Starmer conceded he had ditched support for renationalisation of some industries that he pledged during the Labour leadership election. There is also growing support for Labour to back a change to the voting system that would ditch its historic support for first past the post, used at general elections. Some senior figures are now backing calls for proportional representation. Labour’s affiliated unions had been a barrier to the party supporting a change, but several are now in favour of moving away from the current voting system. High-profile figures such as the Greater Manchester mayor, Andy Burnham, spoke out in the summer in support of a change. Writing in the Observer, he said it would allow more cooperation between political parties on urgently needed social reform. A similar motion on proportional representation was defeated last year, but supporters say that opposition has softened further since then and more unions have backed a change. However, there are figures on the right and left of the party who are opposed to switching away from first past the post. In a vote at last year’s Brighton conference, just under 80% of constituency Labour party votes backed the motion, but affiliated unions and groups overwhelmingly opposed it. The left of the party has also been submitting rule changes designed to ensure the party’s former leader Jeremy Corbyn can stand as a Labour candidate at the next election. Several local branches have supported a change that would enable his return, with his supporters attempting to win support from unions for the measure. Corbyn remains a member of the Labour party, but has had the whip withdrawn, meaning he cannot sit as a Labour MP. Under current party rules, only MPs sitting within the Labour group can stand again under its banner. The change would broaden the rules to include Labour members, handing Corbyn a route back. Without standing for Labour, Corbyn faces a challenge to being re-elected in Islington North. He is said to have significant support among his local party, but officials may well find grounds to throw out the attempts to allow him to stand for Labour again.