LONDON, March 4 (Xinhua) -- Britain's construction activity levels fell to 49.5 in February, the first time the index has been below the 50-mark which separates growth from contraction since March 2018, showed a survey released Monday by IHS Markit/CIPS, a London-based global information provider.

Data showed that the IHS Markit/CIPS Purchasing Managers' Index (PMI) declined to 49.5 in February, lower than 50.6 in January.

Meanwhile, statistics reported a marginal overall rise in new work received by construction firms, with the weakest index reading since May 2018.

The survey suggested that Brexit uncertainty slowed decision-making on commercial projects and led to fragile client demand this year.

Tim Moore, economics associate director at IHS Markit, said: "The UK construction sector moved into decline during February as Brexit anxiety intensified and clients opted to delay decision-making on building projects."

Moor also warned of the impact of more fragile housing market confidence, saying it "has begun to act as a brake on residential work, which adds to signs that house building has lost momentum since the end of last year."

Duncan Brock, group director at the Chartered Institute of Procurement & Supply, said the recent fears over the Brexit-related impacts on the sector were seen in February.

"In short, the foundations of the construction sector are crumbling under the weight of Brexit and businesses are switching to survival mode until the way forward is cleared," Brock said.