Using ropes and scaffolding, steeplejacks will undertake a thorough survey of the 253ft folly before carrying out repairs, which could cost hundreds of thousands of pounds.

"This work should preserve the tower and ensure that it remains a Calderdale landmark for many years to come," said Calderdale Council's regeneration and development spokesman David Kirton (Con, Hipperholme and Lightcliffe).

It is expected to take about five months to partly dismantle and rebuild the top section of the tower, replace missing stone finials and repoint decorative sections and parts of the main tower shaft.

Corroded ironwork will be replaced, the drainage system improved and cracks at the base of the tower will be fixed.

Once work is completed, the council intends to remove the exclusion zone around the towerso it can be opened to the public again on special occasions.

A specialist firm of steeplejacks, Stone Technical Ltd, of County Durham, has been hired to carry out the work.

Wainhouse Tower was built in the 1870s and the 400 steps on the inside lead to the viewing platform.

The cost of the repairs was initially estimated at £350,000 but the final bill will depend on the results of the structural survey.