Nine council politicians and five officers who spent £24,000 on a trip to America have been accused of wasting tax payers' money.
The group from Essex County Council flew business class to Jamestown, Virginia, to mark the 400th anniversary of an English settlement in America.
The council said the transatlantic trip was aimed at forging new trade links.
Matthew Elliott, who heads the TaxPayers' Alliance, said: "This is an appalling waste of taxpayers' money."
The alliance group said it was the last thing councillors should have been doing at a time of rising taxes.
"The taxpayer should certainly not have to pick up the bill," Mr Elliott said.
"It's time people in local government thought about what is really important to taxpayers."
Council leader Lord Hanningfield, who was among the travelling party, said: "The council wanted to use the interest generated by the Jamestown anniversary to create trade and business links between Essex and Virginia.
"We also wanted to encourage more American tourists to explore their Essex heritage."
The council said some of the original Jamestown settlers hailed from Essex.
The £24,000 bill comprised the cost of flights, accommodation and hospitality, the council added.