BRITAIN’S election watchdog has opened an investigation into the Tories, Labour, and the LibDems, over their spending at last year’s snap vote.

Figures released by the Electoral Commission yesterday showed that a total of 75 parties and 18 non-party campaigners spent £41,587,450 on the 2017 General Election – up by about £2.5m on the 2015 poll.

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The SNP spent £1,623,126.63 on the campaign, with mail-outs to voters, and campaign videos being the biggest cost to the party.

The Nicolopter, the helicopter used by First Minister Nicola Sturgeon to fly to six key constituencies on the last weekend of the election campaign, set the party back more than £23,000.

But the SNP’s spending was nothing, compared to the Tories. Not only did Theresa May’s gamble to go to the country cost her party its majority, it also depleted Tory coffers by £18,565,102.

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The eye-watering spend from the Conservatives was far higher than Labour’s £11,003,980 and the LibDems’ £6,788,316.

While not entirely scientific, that means the Tories roughly spent £58,750 for each of their 316 MPs, compared to Labour whose 259 cost £42,486 each, while the SNP’s 35-strong group cost £46,375 each.

It also means the LibDems spent a whopping £565,693 for each of their 12 MPs. The Commission said the Tories, Labour, and the Greens (though not the Scottish Greens) were under investigation for “submitting spending returns that were missing invoices and for submitting potentially inaccurate statements of payments made”.

On top of that, the Tories and LibDems, are being investigated for “making multiple payments to suppliers where either the claim for payment was received past the 30-day deadline or paid after the 60-day deadline following the election”.

One receipt handed over to the Commission by the Tories was for £44 spent at a Nando’s restaurant in Aberdeen. The spending return said £37.78 of that meal should count as spending in England.

The Electoral Commission’s figures cover the 12 months prior to the election on June 8.

Even though none of the parties knew there was going to be an election, anything that would be considered “regulated campaigning” still has to be declared.

The Tories spent £2.1m on Facebook advertising, while Labour spent just £500,000.

The biggest single element of the Conservative spend was £4m, which went to Crosby Textor, the firm run by Tory election guru Sir Lynton Crosby.

In a sign of the decline of Ukip since the EU referendum, the figures released by the Commission show that the party, under Paul Nuttall, spent just £273,104. At the 2015 election, they spent £2.9m.

There will be an investigation, too, into the Women’s Equality Party, which was accused of “submitting a spending return that was inconsistent with its donation reports”.

The pro-EU campaign Best for Britain is also being investigated for not submitting adequate invoices and failing to return a £25,000 donation from an “impermissible donor”.

Teaching union the NUT submitted a spending return that was missing an invoice, the watchdog said.

Bob Posner, head of political fin- ance at the Electoral Commission, said it was “vital that voters are given an opportunity to see accurate and full reportable data on what parties and campaigners spent money on in order to influence them at last year’s General Election.

“This provides transparency in the political finance system and is open for anyone to scrutinise.

“We are investigating possible breaches of the rules. However, our ongoing discussions with the major parties indicate to us that they may wish to consider the robustness of their internal governance”.