Addressing the BLP's 76th Annual Conference over the weekend, Mottley said "It is illegal and it must stop," she said , warning that such action endangered Barbados' future loan repayment ability.
Mottley who was returned un-opposed as leader of the main opposition Barbados Labour Party over the weekend, has called on Barbadians to speak out against the issues facing the island.
She said that Barbadians should become much more vocal about their struggles and to join with her in a movement for a new Barbados.
Mottley pointed out that there was a "growing anger in the country" and accused the government of destroying many of the country's traditional values even as she acknowledged that the power to change the government lies with the voters.
Mottley said there were many issues, including the introduction of tuition fees for Barbadians at the University of the West Indies (UWI), the Municipal Solid Waste tax, the concessions granted to Sandals International and the high fiscal deficit, confronting the island.
"You cannot be a lawmaker and a law breaker too," Mottley said, while also being critical of the decision by the government to sign a memorandum of understanding (MOU) with the Sandals International group providing various concessions. She said the MOU has not been made public.
"Until that MOU is seen, there can be no talk of a level playing field," she warned.
Mottley had taken over the leadership of the BLP from former prime minister Owen Arthur who quit the party in July at the height of public disagreements between the two.
The party honoured former foreign affairs and foreign trade minister Dame Billie Miller, who urged support for Mottley from the party's general membership.
(One Barbados dollar = US$0.50 cents)