Dorset Council and the local police and crime commissioner said the Home Office has failed to answer questions about the Portland Port barge plan.
Suella Braverman’s Home Office faced fresh questions from local Tories about a plan to moor a barge for asylum seekers in a Dorset harbour.
The Bibby Stockholm will house around 500 migrants when it is in position in Portland Port, despite the concerns of Conservative council and police chiefs.
The accommodation barge will head for an assessment and refurbishment in Falmouth, Cornwall, in the coming days before moving into position in Portland in the next few weeks.
But Spencer Flower, the Tory leader of Dorset Council said the authority remains opposed to the plan and said the Home Office has failed to answer questions about the scheme.
Dorset police and crime commissioner (PCC) David Sidwick demanded answers from the Home Secretary about funding for the extra policing that will be required.
The Tory PCC said Dorset Police have started “the necessary and detailed planning required to ensure both asylum seekers and residents will be kept safe”.
“Currently though, they also have detailed questions that need answering and that are necessary to ensure the safety of all concerned,” he said.
“I have been and remain in regular contact with both the Home Secretary and the policing minister with regard to the funding that will be required to meet the extra policing needs that this project will entail.
“I am determined that the funding should not come from the current police budget or from the people of Dorset and I will continue to push the Government to fully fund the necessary security requirements brought about by the decision they have made to site this barge here in our county.”
Council leader Mr Flower said: “Dorset Council’s position has not changed. We still have serious reservations about the appropriateness of Portland Port in this scenario and we remain opposed to the proposals.
“However, like all local agencies, we have statutory responsibilities to fulfil and collectively we want to ensure robust arrangements are in place if this goes ahead.
“We still have unanswered questions which we are waiting for the Home Office and the barge operator to respond to.”
A forum including representatives from national, regional and local public sector agencies and the Home Office is meeting weekly to discuss the plan.
The Home Office has defended the plan, which is part of a series of schemes aimed at moving asylum seekers away from costly hotel accommodation.
A spokesman said: “The number of people arriving in the UK who require accommodation has reached record levels and has put our asylum system under incredible strain.
“We have been clear that the use of hotels to house asylum seekers is unacceptable – there are currently more than 51,000 asylum seekers in hotels costing the UK taxpayer £6 million a day.
“We have to use alternative accommodation options, as our European neighbours are doing – including the use of barges and ferries to save the British taxpayer money.”
Meanwhile, the latest figures showed 88 migrants were detected crossing the English Channel in two boats on Tuesday, taking the total for the year to 6,280.
Prime Minister Rishi Sunak has made a pledge to “stop the boats” one of his key political priorities.