The political wing of the trade union movement has been elected to power for the first time in 14 years.
So many delegates to next week’s Trade Union Congress (TUC) in Brighton will be mixing celebration with anticipation.
But the Labor Party – founded by trade unions more than a century ago – now claims to be the party of business and workers.
This has led to suspicions from some union leaders that Labor’s promised package of work rights will be scaled back.
Well-placed union sources do not believe these fears are justified.
The TUC general secretary publicly hailed the upcoming employment legislation as “the biggest upgrade of workers’ and trade union rights in a generation”.
Paul Nowak to the Labor List website that he has been with the TUC since the 1990s and “I can’t think of a more ambitious program for the world of work”.
The 2016 trade union act will be repealed – removing the participation threshold before industrial action is taken.
The more recent Minimum Service Level Act – to ensure, for example, that some trains will run on strike days – is also headed for the dustbin of history.
But the TUC believes the move is neither anti-business nor too radical.
Mr Nowak told the BBC: “Labor protection in this country is weak compared to many other major economies.
“We urgently need to bring our law closer to the international mainstream. That’s why the government’s Employment Rights Bill is very important.”
Some unions are still hurt that some of Labour’s earlier promises have been ignored.
The proposed ban on all zero-hour contracts has been watered down to ban “exploitative zero-hour contacts” before elections.
But union movement sources said there had been extensive and constructive engagement with the government on the reforms which will go before parliament next month and “no alarm bells were ringing”.
So when Sir Keir Starmer addresses the TUC next week, most delegates will be ready to praise him, not bury him.
But don’t expect the happy era of corporatism to begin.
There will be a flash point.
And with many new Labor MPs maintaining the discipline they did as candidates, it will be in the left-wing TUC, and centre-left, that voices of dissent and discontent will be heard.
Sir Keir’s blushes will survive as some of the more critical debate is expected to take place before his arrival or after he has left.
There will be a debate about withdrawing most pensioners from the Winter Fuel payment – with calls for a rethink, or to reduce this for those who do not receive Pension Credit but still have less.
It was written up for discussion on the same day as the Commons vote on the policy.
But there will also be more fundamental challenges to Rachel Reeves’ economic management.
The move from the country’s second largest trade union – Unite – said more needs to be done to fix the “broken economy” than wait for economic growth.
So they are calling for the richest 1% to be subject to a wealth tax – which would cover the “black hole” the government says exists in public finances.
Unite general secretary Sharon Graham told the BBC: “Why is Labor picking pensioners’ pockets in winter fuel payments instead of making the people with the biggest shoulders pay?”
They claim a 1% tax on the top 1% in society would raise £25bn a year.
The union also called on Labor to make “different choices” – including the kind of “serious state investment” that would reduce or potentially undermine the Chancellor’s fiscal rule.
And a motion from the RMT rail union specifically called for “arbitrary” and “restrictive” rules to be reformed.
A shot will be fired across the bow of Labour’s “green transition” policy.
The country’s second and third largest trade unions – Unite and GMB – are concerned about jobs in the oil and gas industry.
Former unions claim 30,000 jobs are at risk and are opposed to ending new oil and gas licenses in the North Sea without guaranteeing alternative employment.
The latter union is calling for an energy strategy that includes not just nuclear and renewable energy, but “oil and gas production,” saying that “gas remains essential to power British manufacturing”.
Sources indicate that the union prefers to achieve its goals through negotiations rather than open confrontation.
But Unite is becoming too public to raise concerns.
Sharon Graham has suggested oil and gas workers risk the same fate as miners in the 1980s when many of the country’s pits closed and communities saw unemployment rise.
He said: “Everyone knows we have to do something about the climate crisis.
“But workers cannot be sacrificed on the altar of net zero. North Sea jobs are on the edge of the cliff.”
The shop trade union Usdaw is usually quite loyal to the Labor leader – and direct criticism of the government from its leader was not anticipated.
But the union is calling for the two children’s benefit caps to be lifted.
A similar call from seven Labor MPs led to a temporary suspension from the parliamentary party, when it voted with the SNP on the matter after the election.
And Usdaw wants to see more ambitious plans to tackle poverty.
Union leader Paddy Lillis said: “We are calling on the Labor government to urgently improve social security and funded labor reforms by calling on task forces to pay for work, end poverty, offer proper safety nets and promote equality.”
The bigger question is how much influence the union will have. Labor has expanded its donor base and is less dependent on union funding.
Sources confirmed that although some critical moves were made, few would have expected the Labor leader to easily and quickly concede to the demands.
The labor rights agenda has helped generate goodwill.
But in some areas – particularly on the journey to net zero – tensions remain.
And where jobs are under threat in other industries – particularly steel – calls for the new government to do more are unlikely.