The Construction Confederation is calling for a stay of execution on penalties for late tax returns, which could cost the industry as much as £7m.

Liz Bridge, head of tax at the confederation, was due to ask for a two-week extension at a meeting with HM Revenue & Customs yesterday, in light of delays caused by postal strikes.

If returns are not filed by the cut-off date today, contractors will be fined at least £100. In September, 166,000 returns were expected but only 95,000 applications came in on time.

A spokesman for the revenue said the strike was beyond its control but it would “consider cases sympathetically”.