Jim Murphy, one of Labour's most senior MPs, suspended his Scotland-wide speaking tour in support of the union after coming under verbal and physical attack from yes voters.

He made his decision a day after he was pelted with eggs in Kirkcaldy on Thursday, in some of the ugliest scenes of the referendum campaign, during a 100-day street speaking tour to make the case for a no vote.

"What is happening is that the yes campaign are now organising to create a mob atmosphere at our street meetings. It's coordinated, it's determined and it's increasingly aggressive," he said.

Announcing he had suspended his street meetings tour for 72 hours, Murphy accused yes campaign groups of orchestrating confrontations, which had sharply escalated since the first minister, Alex Salmond, was seen to lose his first TV debate against Alistair Darling.

The surge in hostility suggests that tensions are rising as the 18 September referendum date nears, although the Yes Scotland campaign was swift to make a public condemnation of these incidents.

On Wednesday, Gordon Brown, the former prime minister, was verbally abused by a yes voter at a pro-UK rally in Dundee. Salmond's office responded by disclosing that his staff had called police earlier this month after his car was tailgated at speed by one angry no voter on the A90.

The yes campaign said it opposed "all forms of abusive, dangerous and offensive behaviour" and said it has now privately warned several groups named by Murphy about their conduct.

"For the most part, the independence debate has been conducted in a responsible, peaceful and enthusiastic manner, with only a very small minority on both sides behaving badly," the campaign added.

The number of yes activists arriving at his street-corner rallies suddenly grew, drowning out undecided voters and no supporters, he said. In some cases, protests were being arranged by Yes Scotland groups on Facebook encouraging activists to give him "a warm yes welcome", he alleged.

"What started as individual passionate nationalists having their say has changed into angry mobs of nationalists coming along and making sure that no one else has their say," Murphy said.

One of the most active Better Together campaigners, Murphy, a former UK secretary of state for Scotland, has taken two Irn Bru crates on a "100 towns in 100 days" tour of high streets and town squares in a modern take on traditional soapbox tours. Until now, they have been good-humoured and civil.

He was due in Selkirk, Peebles and the Edinburgh area this weekend, but has suspended the tour to get police advice and to train his staff on personal protection, Murphy said.

"It also gives 72 hours to the Yes Scotland campaign to call off their mobs. The blame for this is at Yes Scotland's door." Murphy added: "It's not about an egg. I'm not a coward, I won't be silenced and I won't surrender the streets to them."

Despite the row, last week was largely good for the yes side following Salmond's victory in the televised leaders' debate against Darling, leader of the pro-UK group Better Together.

A poll by Survation for the Daily Mail on Friday again lifted the yes camp by showing a bounce in support for independence, with a slim seven-point gap between yes and no, putting them at 47% to 53%. This is close to the highest yes vote found by Survation, a polling company that has tended to produce results more favourable to the yes vote than other pollsters.

But Salmond then found himself under attack after appearing to again rewrite Scottish government policy on a currency union by claiming that "we haven't argued that it was the currency that was the asset" in a phone-in on BBC Radio Scotland.

The notion that sterling is a shared asset has been a key plank in Salmond's case that Scotland has a clear moral and legal case to have a formal currency zone, but it has been challenged by senior economists, who say a currency is only a system of exchange or a liability.

Salmond's claim was ridiculed by Ruth Davidson, the Scottish Tory leader, after Better Together published a series of quotes from the first minister, his deputy, Nicola Sturgeon, and the SNP's Treasury spokesman, Stewart Hosie, all stating that sterling is a "shared asset".

• This article was amended on 31 October 2014. In an earlier version, a photo caption said the picture showed "Jim Murphy being hit with an egg". In fact, according to reports of the court case against the egg-thrower, that egg and others thrown at the MP missed, although he was hit with another egg that was struck directly against his back.