Labour's biggest union donor has been spotting cosying up to Nigel Farage in a secret meeting earlier this week.
Officials from Unite held their first direct meetings with Reform UK's top brass, which have been described as "constructive".
The Reform UK leader's allies have hailed the meeting as a "significant step" towards solving the year-long walkout of Birmingham's binmen, with the talks focusing on the ongoing dispute over pay.
Residents have been up in arms over Europe's largest council inability to bring the long-running dispute to an end.
Rubbish-ridden residential streets have attracted rats as big as cats - as well as politicians looking to capitalise on voters' disillusionment with Birmingham City Council in the upcoming local elections.
Unite, historically one of Labour's largest union donors, has defended the demands of the binmen, who initially walked out over pay.
The union, led by Sharon Graham, has criticised Sir Keir Starmer's party for dragging its feet on paying the bin workers.
The leading union has now cut its affiliation fee by 40 per cent, reducing funds from £1.45million to £870,000, a move which the union said "shows the anger of Unite members".
Sharon Graham joined the protesters last month
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Ms Graham suspended working class champion Angela Rayner from the major union over her handling of the crisis, while the union sought to "re-examine their relationship" with the party.
Labour, which prides itself on being the voice of the working class, has now been spurned further by Unite - with its top brass being spotted in a "secret meeting" with Sir Keir Starmer's rival, Nigel Farage.
A spokesman for Reform told The Times its "administration in Birmingham will rapidly get round the table with Unite to agree a solution" if they were to win control of the major council when Britons cast their vote in May.
Latest polling from More in Common has indicated Mr Farage's party could come second in the council that has been Labour-run for 14 years.
REFORM UK LATEST:
Nigel Farage is currently on the campaign trail
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The data has suggested Reform UK would win 26 Birmingham councillors on the local authority, while Labour would win 32.
The Conservative Party would be pushed into third - and the council is set to have no overall control.
Ms Graham, however, did not attend the Reform rendez-vous in Birmingham.
Previously, the trade union chief declared she would "talk to the devil himself" if it was necessary to strike a deal for the workers.
The party's spokesman added that, if elected, Reform UK vowed to "resolve the bin strike and end the absurd waste of millions of pounds of agency staff".
They said they would "prioritise more appropriate, stable, permanent jobs that offer better conditions for staff and better value for taxpayers".
A Reform spokesman told The Times: "The council has wasted £34million already on this dispute.
"They have argued about the legal risks involved, but while Unite have published their legal advice on equal pay, the council has not produced any evidence or provided documents to back up their arguments.
"We call on the council to be transparent and share its legal advice now. This is vital to enable a new Reform UK administration to hit the ground running and get this settled in May."