KEIR Starmer launched an attack on the SNP over the Peter Murrell scandal as he dodged questions over his "paper thin" defence investment plan.
Last week, the former chief executive of the SNP was sentenced to more than five years in jail after pleading guilty to embezzling more than £400,000 from the party over a 12-year period.
The Scottish Parliament rejected a call for an inquiry into Murrell's crimes last month, instead backing a wider probe into the financing of political parties.
At Prime Minister's Questions, SNP Westminster leader Dave Doogan criticised Starmer's "paper thin plan" for defence investment.
The £15 billion plan was set out in a speech on Tuesday and will see road and energy projects scrapped to pay for the military.
The plan also promises a £64bn upgrade to Britain’s nuclear deterrent.
"I am gravely concerned that time and time again this Prime Minister in response to the abject and honest criticism of his defence investment plan, he cites recent trends in defence spending, when he should be calibrating it against the chronic and very real threat that the people of these islands face," he said.
"In his limited time left in Number 10 will he get a grip of his paper thin plan?"
Instead of answering the question, Starmer hit out at the SNP's anti-Trident policy before launching into an attack on Murrell and the lack of a Holyrood inquiry.
"This is the party that thinks we should give up the nuclear deterrent and he stands there to talk about defence, so we need no more advice and sanctimonious nonsense," Starmer said.
"Before he or any of them give any more advice to me or this House, let's have some home truths.
"Their chief executive has just been jailed for five years for embezzlement. They're all pretending they didn't know anything about it. They couldn't even see the motorhome parked in the driveway apparently, and now they're blocking an inquiry in the Scottish Parliament.
"Before they offer any more advice, they should look in the mirror."
Scottish Labour argued an inquiry was required "to restore public trust in Scottish politics" but this was rejected by MSPs.
The parliament ultimately backed a motion supporting an independent review into the finances of all parties and the influence of wealthy donors.
The Green proposal was passed with the backing of SNP MSPs, though it is not binding.
Elsewhere at PMQs, LibDem leader Ed Davey asked Starmer about the "rising tide of racist violence and hate" in the UK.
He said he was told by a British friend of Indian ancestry that Reform UK "activists" came to her door and said that if their party gets into power her family will have their passports seized and citizenship revoked.
Starmer said racism and intolerance is "permeating everywhere" and it should be called out by every single person who is a politician "at any level in this country".
