A busy Southall road closed in September will not open again until March next year - four months later than anticipated.
Park Avenue was closed on September 12 earlier this year due to a faulty pipe, with signed diversions displayed in Uxbridge Road and South Road.
National Grid said the road, which stretches 0.8 miles long, would be reopened eight weeks later.
But now the utilities company have said the road will continue to remain closed until March 2017, after engineers found that the corrosion of the pipe was worse than originally thought.
'We have no alternative'
National Grid gas distribution network engineer, Brent Tattam, said: "This pipe plays an important part in supplying gas for cooking and heating to the local area so the work to repair the corrosion is vital.
"Once work got underway we found that corrosion of the pipe was more extensive than our initial surveys had indicated therefore we’ve had to extend the work.
"We’re sorry for any inconvenience this may cause and will do all we can to keep disruption to a minimum.
"Where possible we avoid large excavations and road closures.
"However because of the pipe’s size, location and the type of repairs needed we have no alternative but to dig down to it and close the road."
The closure has been put on hold this weekend (November 5/6) until Monday (November 7), so Southall's Nagar Kirtan procession, where thousands of Sikhs will line the road and surrounding streets to celebrate Vaisakhi , can go ahead.
Access to be maintained for residents
Because of the gas pipe's size, location and the repairs needed, engineers will use specialist kit to dig large scale excavations five metres deep.
National Grid said the repairs are needed to ensure safe and reliable gas supplies for cooking and heating is maintained.
It also said access will be maintained for residents, businesses and local facilities while the repairs take place on the road.
More information on the closure can be found here .
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