Contractors have contacted the Enquirer to vent their frustration with the problems which have been ongoing since late last month.

One said: “Their portal has been playing-up for a while and is causing potential problems with payment delays and contract awards.”

Constructionline confirmed its platform “has been experiencing periodic performance issues since the 21st October.”

The issues have been caused by a surge in demand for the new Common Assessment Standard being introduced across the industry.

The new common pre-qualification system for subcontractors has been made available to all 47,000 suppliers on the Constructionline platform.

Thousands of firms have taken up the offer and the “higher than anticipated” demand has swamped the system.

Introduction of the Common Assessment Standard coincided with the new Constructionline Verified VIP membership which led to “a large surge of suppliers” looking to gain the enhanced level.

Constructionline said: “We fully appreciate the level of impact this is having on some firms using the platform, we are continuing to work closely with our technology partner to improve the performance of the platform.

“We continue to recommend that where possible, suppliers should access the system outside of peak hours (0900-1700) where the performance is fully in line with normal performance.

“We sincerely apologise to anyone who has experienced any issues regarding this, and we share in their frustrations however, we are hopeful that we will resolve all issues shortly.”