Police in Derbyshire have urged the British National Party (BNP) to tell them where in the county they intend to hold their annual conference.
On Tuesday, the party confirmed it would hold its conference in South Derbyshire in December but would not confirm an exact location.
Supt Gary Parkin said the force needed to put in place "appropriate resources" near the venue.
The BNP said Derbyshire had been chosen because of its central location.
John Walker, press spokesman for the BNP, said the actual location had not been finalised.
He said: "We've got quite a lot of members in the Derbyshire area and the east and West Midlands. It is a popular area for us and a central location.
"Things are still in the planning stages and this is the decision the party hierarchy has made, possibly on security grounds."
He added they would be expecting about 500 people to attend the conference.
Mr Parkin said: "We need to know what sort of venue this will be at and how many people will attend so we can start the planning stage and put the appropriate resources in place.
"Every event has a cost but this is a party that attracts a certain degree of protest so there will be costs involved. We are in touch constantly with the BNP to see if we can confirm or deny where it will be held," he said.
For three years Denby in Derbyshire hosted the party's Red White and Blue Festival, which in 2009 cost about £500,000 to police.