Home buyers and developers could face even greater delays than usual because of a work to rule by 130 technical staff at the Land Registry, which began yesterday.
Staff shortages at the registry are causing long delays in processing applications, and there is a backlog of 145,000 cases, according to IMPACT, the union representing staff.
The current property boom has caused a 60 per cent increase in Land Registry business, and the union claims productivity has increased by 20 per cent. However, it wants more technical staff to deal with "the vast increase in workloads".
IMPACT's assistant general secretary, Mr Peter Nolan, said members would refuse to approve scheme maps or make maps available to the public under the work to rule. Staff would also refuse to deal with telephone queries. Hardest hit will be sales of new houses and apartments.
The dispute is over management's failure to name and appoint 27 staff members awaiting promotion since last month.
"Staff are not looking for anything that has not already been agreed by management, yet this is the third time the union has been forced to threaten industrial action on this matter," Mr Nolan said.
"Clearly Land Registry management is incapable of managing its staff relations properly, and I am calling on the Department of Justice to enter urgent discussions on this problem."