The Observer claims the independent police watchdog has delayed its announcement on whether Boris Johnson should face an investigation into possible criminal misconduct in his relations with US entrepreneur Jennifer Arcuri until after the election.
The paper reports that Westminster politicians and London assembly members believe the ruling has been "suppressed" in order to protect the PM from damaging headlines ahead of polling day.
The Independent Office for Police Conduct has issued a statement strongly rejecting the paper's claims and insisting that the matter is still being decided.
Meanwhile, many of Sunday's papers hone in on the Conservatives' analysis of Labour spending pledges.
"Scale of Labour's reckless spending revealed" is the headline in the Sunday Telegraph. It should be noted that the document, produced by the Tory party, assumes that all Labour policies passed at the party's annual conference will be included in its manifesto.
The Telegraph quotes Chancellor Sajid Javid as saying the Tory research sets out "the numbers Labour did not want you to see".
"Terrifying bill for nation revealed" is the lead in the Mail on Sunday, which tells its readers that Labour's plans would cost every household £43,000.
The paper alleges that the Tory dossier - largely based on previous manifesto commitments - has been produced with the help of civil servants, prompting "furious objections" from shadow chancellor John McDonnell.
Online, Mr McDonnell provides the lead for the Independent. In an interview, he pledges that the Labour manifesto - to be presented in the coming days - will be the party's most radical ever.
It will, he claims, include plans to introduce a universal basic income, and drastic measures to tackle the climate crisis.
He also denies reports that there've been strained relations between himself and Jeremy Corbyn in recent months.
Several papers carry pictures of the partly submerged village of Fishlake near Doncaster after it was evacuated yesterday because of life-threatening flooding.
The Mail on Sunday devotes a double-page spread to conditions in the area which saw the River Don flood after a month's rain in a day - warning that snow is now forecast in the coming days.
The Sunday Times reports that the successful Netflix series The Crown has been accused of "muckraking" in its latest series - to be released next week.
Under the headline "Crown slammed over Queen's 'affair'", it sets out the objections of the Queen's former press secretary, Dickie Arbiter, to one of its storylines that portrays a close relationship between the Queen and her horse racing manager, Lord Porchester.
Declaring it "gossip that's been washing round for decades with no substance" Dickie Arbiter says the Crown's scripts are known for being "beefed up" but he condemns the portrayal of the friendship as "distasteful and totally unfounded".