Rick Santorum wants David Cameron to know that he was first to lay claim to the "blue collar conservative" catchphrase.

A week after the British prime minister tried to rebrand his new government as a champion of the workers, the former US senator from Pennsylvania was on the campaign trail in Iowa, trying to pull off a similar trick for Republicans.

Four years ago, Santorum ran for president as a social conservative. He won the state of Iowa but ultimately lost the primary election to a candidate – Mitt Romney – who came to be seen as a man of the wealthy rather than a man of the many.

Since then, Santorum, like others on the right of his party, has tried a different approach to recapture working class Republican voters – a focus he first outlined in a 2014 book called Blue Collar Conservatives.

"If [Cameron] did steal it from me, I'm flattered," Santorum told the Guardian after trying out the message on Republican members of the Pachyderm Club in the small Iowa town of Marshalltown.

Some of Santorum's policy prescriptions, such as lower taxes and regulation, sound suspiciously similar to the old ones. Certainly, many on the left will remain as sceptical of this rebranding of the former Pittsburgh lawyer and lobbyist as they are of the Eton-educated prime minister's supposed conversion in London.