A prominent union leader is intensifying pressure on Sir Keir Starmer to consider re-entering the EU customs union, advocating for the tightest economic ties possible with the European bloc.

Paul Nowak, who heads the Trades Union Congress and holds the title of the UK’s top trade unionist, urged the government to explore ‘every conceivable’ avenue to strengthen relations with the EU, including a potential return to the customs union.

During a conversation with the BBC, Nowak emphasized that the Prime Minister should aim for the ‘closest feasible economic and political ties with the European Union’ as the year 2026 approaches.

While Labour’s election manifesto clearly states opposition to rejoining the customs union, internal friction on this matter is becoming increasingly apparent within the government.

The Prime Minister previously expressed a desire to ‘reset’ the UK’s rapport with the EU, a sentiment that was taken a step further by his Health Secretary, who is often seen as a potential leadership contender.

In an interview with The Observer on Sunday, Wes Streeting suggested he might like to see a return to the customs union, saying the best way to boost the economy would be a ‘closer trading relationship’ with the EU.

‘The reason why leaving the EU hit us so hard as a country is because of the enormous economic benefits that came with being in the single market and the customs union,’ he said.

‘This is a country and a Government that wants a closer trading relationship with Europe. The challenge is that any economic partnership we have can’t lead to a return to freedom of movement.’

Paul Nowak, the leader of the Trades Union Congressand the most senior trade unionist in the UK, said the government should look at ‘every possible’ opportunity for relations with the EU

Sir Keir Starmer is facing Cabinet splits over the issue, but Downing Street says it will stick to Labour’s manifesto, which ruled out rejoining the customs union

And earlier this month 13 Labour MPs rebelled against Starmer and support a motion from the Liberal Democrats calling for negotiations for a bespoke customs union arrangement. 

But Downing Street claims it is still committed to its manifesto pledge and the UK will not rejoin any such agreement anytime soon.

Now trade unionist Mr Nowak has become the latest voice to put pressure on Starmer.

‘Absolutely the Government should rule nothing out,’ he told the BBC. ‘They should look at every option for our relationship with the European Union, up to and including a customs union.

‘I go round workplaces week in, week out – aerospace, automotive, steel – and having a good deal with Europe is essential.’

Mr Nowak added: ‘2026 really needs to be the year when the government gets to grips with the cost of living crisis.’ 

He also argued that a closer relationship with Brussels has become ever more important since Donald Trump returned to the White House, arguing the President is not a ‘reliable ally’ to Britain. 

As head of the TUC, Mr Nowak represents 47 trade unions with a collective membership of more than five million, having taken up the role in 2023. 

His comments on the customs union are sure to make an already tricky situation for Starmer even more difficult.

The Conservatives and Reform UK vehemently oppose rejoining, arguing that any such move would essentially hand control of Britain’s ability to negotiate bespoke trade deals with other countries back to the EU. 

But Labour will also be keen to keep the unions onside as they make up an important part of the party’s membership and funds – giving around £10 million last year.

Yet if the UK were to rejoin the customs union, it would likely have to adopt the EU’s tariff rates, including the higher tariff imposed on imports from Europe by the US.

It is also unclear what would happen to the trade deals secured with countries outside of Europe since Brexit. 

As well as his comments on trade, Mr Nowak also had a message for the government on the rising influence of Nigel Farage’s Reform UK.

He said Starmer should not try to match Farage’s immigration policies and that the solution is not to try and ‘out-Reform Reform’. 

‘My job isn’t to tell union members they have voted the wrong way. The responsibility is on the government to demonstrate that mainstream politics can deliver the change people want,’ Mr Nowak said.