The A303 can be nightmare for tourists in the holiday season

The combination of dual and single carriageway on the A303 from Honiton in Devon to the M3 causes horrific jams in the summer as people flock westwards for their holidays.

The Highways Agency is expected to report on two options, dualling the A358, which links the M5 to the main A303, or dualling the A303 through the Blackdown Hills, an Area of Outstanding Natural Beauty.

The proposals have caused friction between business leaders in Devon and Cornwall and Somerset.

Somerset business leaders want the A358 between Ilminster and Taunton to be dualled.

They say dualling the A303 through the Blackdown Hills would mean delays for inquiries and the certainty of environmental protests.

Stephanie Berry of Somerset Chamber of Commerce, said: "It's a strategic route which can serve quite a wide geograpic area in the South West and would give links from the south coast ports to the Midlands.

"It's not just a Somerset issue, it's a regional issue."

But Devon and Cornwall business leaders, pointing to a resurgence of holiday traffic, especially to Cornwall, want the A303 to be dualled.

Neill Mitchell of the Devon and Cornwall Business Council, said: "Our tourism industry is now a 12 months-a-year business and journey times are very important.

"If we are going to win people away from Oxfordshire and the Midlands we need to have a good journey time from the South East to the South West."