National Highways has issued delay warnings ahead of over a month of roadworks on key Wiltshire roads, including the M4.

Several key roads around the county will be hit by full or partial closures between now and the start of October, while maintenance work is carried out.

The most disruptive of these closures are expected to cause delays of up to 30 minutes.

As National Highways is responsible for maintaining motorways and major A-roads, closures of smaller roads are not included in their schedule.

READ MORE: Swindon drivers warned of delays as month of closures to hit A419

A full list of ongoing and upcoming roadworks can be found below.

• M4 eastbound – From 8pm to 6am between August 19 and August 31, slight delays caused by lane closures between junctions 18 and 17.

• M4 eastbound – From 6am to 8pm between August 20 and August 30, hard shoulder closure for barriers between junctions 18 and 17.

• A303 – From 8pm to 6am between August 20 and August 23, 10-30 minute delays: A36 closed at Wilton Railway Bridge for Virgin Media works. Includes lane closure on the A36 southbound, at Deptford.

• A303 - From 8pm to 6am between August 20 and August 23, 10-30 minute delays: A303 westbound, Parkhouse to Countess or Solstice Park exit and entry slip closures for carriageway repairs.

• M4 eastbound - From 8pm on August 22 to 6am on August 23, slight delays, junction 15 to Membury Services during lane closure for maintenance works.

• A303 - Between 9pm and 5am, from August 27 to August 29, 10-30 minute delays: A303 both directions Deptford to Longbarrow Roundabout carriageway closures for resurfacing.

• M4 eastbound – Between 8pm and 6am from September 1 to October 3, slight delays caused by lane closure for barriers between junction 18 and junction 17.

• M4 eastbound – Between 6am and 8pm, from September 2 to September 30, slight delays between junction 18 and junction 17 due to hard shoulder closure for barriers.

• M4 westbound – From 8pm on September 2 to 6am on September 3, slight delays between junction 16 and junction 17, during lane closures for electrical works.

• M4 eastbound – From 9pm on September 2 to 6am on September 3, slight delays between junction 17 and junction 16 due to lane closure, for electrical works.

• A303 – Between 9pm and 6am, from September 2 to September 5, 10-30 minute delays: A303 eastbound, Longbarrow to Countess closed for maintenance works, diversion via A360, The Packway, A345 and vice versa.

• M4 eastbound – from 9pm on September 2 to 6am on September 3, slight delays between junction 17 and junction 16 due to lane closure for electrical works.