Heckle the PM... get £15m for flood defences

Kent village scheme is one of many infrastructure projects to be unveiled this week – including a road tunnel under Stonehenge

A tunnel under Stonehenge and £15m of flood defences for a Kent village where David Cameron was heckled last Christmas will be included in four days of infrastructure spending announcements this week.

Danny Alexander, the Liberal Democrat Chief Secretary to the Treasury, plans to unveil 100 road projects worth £15bn, £2.3bn for 1,400 flood defences, and tax breaks for North Sea oil companies. Announcements of infrastructure projects are usually made a day before Chancellor George Osborne unveils his Autumn Statement. But this time Mr Alexander will spread a series of announcements over the week to make sure the LibDems receive publicity for the plans.

Nick Clegg and his top team are frustrated that the Tories have received the credit for most of the coalition's economic successes, so are ensuring this is not repeated, given Mr Alexander chairs the Cabinet's Infrastructure Committee.

"In the run-up to the general election the Lib Dems have got to fight for greater credit," said a Whitehall source. "Wouldn't it be exciting if a tunnel under Stonehenge was announced?" That announcement could be made as early as tomorrow, when Mr Alexander is expected to give details of the roads projects, which will bring hundreds of extra miles of lanes to UK motorways and trunk roads.

The Stonehenge project would relieve congestion on the A303, and comes seven years after similar proposals were dropped over costs. The plan has the support of the National Trust, which wants the longest tunnel possible to negate environmental blight and prevent traffic bottlenecks near a World Heritage Site.

The Prime Minister was berated during a visit to the Kent village of Yalding last year during the winter floods. Around 100 homes had to be evacuated on Christmas Eve and Christmas Day when rivers burst their banks. Resident Erica Olivares told Mr Cameron that she was "absolutely disgusted" by the lack of response from government agencies. She said the village was "literally abandoned". Mr Alexander faced similar comments when he visited in February.

At the time, Kent County Council leader Paul Carter effectively dared Mr Alexander into putting up money for new flood defences by promising the authority would match the Government 50/50 out of local taxation. He said it would cost about £30m to protect Yalding and its vicinity.

The Whitehall source noted that Yalding is also in a constituency that is expected to be a straight LibDem-Conservative fight in May's election. Tory Helen Grant held the seat in 2010, but on a substantially reduced majority of 5,889 after the Lib Dems' vote share rose by 13.2 per cent.

On Tuesday, Mr Alexander will make a speech to the Institution of Civil Engineers, where he will outline the flood-defence proposals and give an update on the National Infrastructure Plan. This is a list of 40 of the most important infrastructure projects, such as the Mersey Gateway bridge, a £2bn project to replace the 53-year-old Silver Jubilee Bridge that links Runcorn and Widnes, and the electrification of rail lines, including those in the Welsh Valleys.

On Wednesday, Mr Osborne will make a plea for a Conservative election victory by saying: "Now our economy is growing faster than any other major economy in the world – and we've got a record number of people in work. We must not throw this away and go back to square one… Let's finish the job."