LIBERAL Democrat MSP Alex Cole-Hamilton is being called upon to resign his party whip amid a police investigation concerning alleged “financial irregularities” in his election expenses.

The former charity worker, who won the Edinburgh Western Holyrood seat in May, was reported to Police Scotland earlier this month and faces allegations of submitting an inaccurate spending return under-declaring his campaign costs.

Angus Stewart, spokesman for the SNP’s Edinburgh Western branch, urged Cole-Hamilton to resign the party whip while police inquiries were ongoing.

Stewart said: “Given that Alex Cole-Hamilton is personally under investigation over his expenses it is right and proper that he resigns the party whip while the police establish if any wrongdoing has been committed.”

It is understood a member of the public gave a statement claiming Cole-Hamilton filed an inaccurate spending return that under-declared his campaign costs. Police have said they are establishing if any “criminality” took place.

The LibDems have said all spending was within the election rules and have said neither Cole-Hamilton nor his agent have been contacted by the police.

SNP activists are angry Cole-Hamilton has not resigned the party whip after MP Michelle Thomson resigned the SNP whip amid a police investigation into property transactions connected with her business.

Her solicitor was struck off for misconduct and the episode is believed to have damaged the SNP’s Holyrood campaign. Next week the SNP’s ruling body is due to hear a request from MPs to reinstate Thomson to the party after police said she is not under investigation.

“In my view the Lib Dems ran the dirtiest campaign they have ever seen – and it was all about Michelle Thomson, who had nothing to do with the Holyrood elections,” said one SNP member in the constituency.

“It’s a disgrace that Alex Cole Hamilton hasn’t resigned the whip while he is personally investigated by the police. Michelle Thomson was never even questioned by the police and yet she did the right thing and resigned the SNP whip.”

Edinburgh Western has been closely fought by the LibDems and the SNP in Holyrood elections over the past ten years.

It was won by Margaret Smith for the LibDems in 2007, then by Colin Keir for the SNP in 2011 before Cole-Hamilton won it back for the LibDems this May.

Tipped as a future LibDem leader, the 39-year-old was a “dual candidate” in this year’s Scottish Parliament election, standing both in Edinburgh Western and on top of his party’s regional list for the Lothians.

Electoral Commission guidance says dual candidates must make “an honest assessment” of whether their spending promotes their constituency or regional campaign.

Last weekend it emerged Cole-Hamilton recorded the highest spending of any candidate in Edinburgh, spending £32,549 on his campaign, 75 per cent more than his nearest rival, SNP candidate Toni Giugliano, who spent £18,593 in the fight to win the Edinburgh Western seat.

In the last leg of the campaign Cole-Hamilton came within £543 of the legal spending cap.

The National’s sister paper the Sunday Herald reported that Cole-Hamilton stayed under the threshold by attributing thousands of pounds of leaflet and office costs to the Lothians regional fight instead of counting it toward his constituency campaign.

However, many of the leaflets claimed by the LibDems as regional spending were weighted towards Edinburgh Western and named specific neighbourhoods in the seat.

One bill of almost £1,000, for 38,500 copies of the West Edinburgh News, was attributed 39 per cent to the party’s Lothians-wide fight and 61 per cent to Cole-Hamilton’s constituency. Cole-Hamilton beat the SNP by 2,960 votes and is now his party’s health spokesman.

A spokesman for Police Scotland said: “We are investigating an allegation of financial irregularities. Our inquiries into this matter are ongoing as we work towards establishing if any criminality has taken place.”

A LibDem spokesman said: “All campaign spending during the election was forensically and properly recorded through detailed accounts. Everything is fully within the rules. The police have not contacted Alex Cole-Hamilton or his agent.”

Thomson resigned the party whip and had her SNP membership automatically suspended last year. She now sits as the Independent MP for Edinburgh West. She has denied any wrongdoing.

She ran the pro-independence Business for Scotland group during the 2014 referendum campaign and was one 56 SNP MPs elected in the party’s 2015 General Election landslide.