The papers: Missing child sexual abuse files and the Yorkshire Tour de France
Claims of a "Westminster paedophile ring" and an "establishment cover-up" again make the national press, with the news of 114 missing Home Office files about an investigation into child abuse allegations.
The missing files - which are either "lost, destroyed or simply 'not found'" - relate to a Home Office investigation into allegations made in a dossier compiled by the late Conservative MP Geoffrey Dickens, the Sunday Telegraph says.
The dossier itself is now missing. It contained allegations which Mr Dickens said would "blow the lid off" the lives of rich and powerful child abusers, the paper reports.
It adds that Home Secretary Theresa May has been urged to "get involved" in the investigation into how her department came to lose the material.
In a feature on the Dickens dossier, the Sunday Times said the parliamentarian, who died in 1995, was a "colourful, rent-a-quote MP, who was often mocked for malapropism" but who "fought a serious and determined battle to protect children from sexual abuse".
The Times says Mr Dickens received a "backlash from fellow MPs" after using parliamentary privilege to name a senior British diplomat as a paedophile. The man was subsequently arrested.
The MP's son, Barry, tells the paper that because of his work on trying to uncover abusers his father received "many death threats" and that two burglaries took place in his constituency and London homes, but nothing of value was taken.
The Sunday People says Mr Dickens' name was found in a notebook owned by a man who was subsequently jailed for three murders. The killer had also been spotted near the Dickens' family home, Barry Dickens told the paper.
In a related story in the People, MP Tom Watson who raised the issue of a paedophile ring in Westminster in a parliamentary hearing in 2012, said the Dickens dossier is a "tiny part of bigger allegations" and he called on David Cameron to set up an "overarching national inquiry" into the issue.
The Mail on Sunday carries claims that the names of 10 current and former politicians were in the documents Mr Dickens compiled.
In the paper, Simon Danczuk, the MP who exposed the late Cyril Smith as a child abuser, writes that "if MPs have harboured paedophiles, the damage to British democracy will be fatal".
Mr Danczuk says "in the higher echelons of party politics... my impression is there is little appetite to confront the abusers in their midst.
"The mood is defensive, the approach is dominated by silence. 'Move along, nothing to see here' or 'what is the point in raking all that up, old boy' is the attitude I have seen time after time."
In the Sunday Mirror, Mr Danczuk makes a plea to serving and retired police who have knowledge of earlier investigations into a Westminster paedophile ring to come forward.
"Tour De Force" is how the Daily Star Sunday describes the weekend's big sporting event in Yorkshire.
The paper says more than a million fans watched the Tour de France's "grand depart" from Leeds and the 198 riders progress through the picturesque Yorkshire Dales to Harrogate.
"The real winner had to be the Yorkshire Tourist board. It looked reet nice on TV," the paper comments.
The Observer doubles the spectator estimate to two million noting some of the sights riders in the peloton would observe on their progress: knitted cycling jersey bunting; French, English and British flags; yellow-sprayed bicycles; polka-dot-painted pubs and in one village, cardboard bikes in a graveyard.
French sports journalist Francois Thomazeu, writing in the paper, hails the British conversion to "knowing almost as much about the Tour" as the French, "perhaps, even a little more".
"Yesterday it seemed as though the whole of Yorkshire had left their homes to act as a guard of honour to the peloton.
"Will cycling really be coming home on Tuesday when the Tour heads back to France?" he muses before concluding, "I'm not so sure any more."
The Observer also profiles Gary Verity, the tourist chief responsible for floating the idea of bringing the Tour to his home county.
"What could we do in Yorkshire that would be globally massive?" had been his challenge, the paper says.
Whilst hailing the "Tour de Yorkshire", the Sunday Times predicts that "London could grind to a standstill" on Monday, when the race reaches the capital.
More than 100 schools have closed, hospitals along the route have cancelled all but emergency operations and much of central London will be closed between 10am and 6pm, it adds.
However, the upside, the paper says, is an estimated £100m economic bonus from the presence of the Tour.
"The biggest crackdown on unions for 30 years" is being planned, according to a story in the Mail on Sunday.
The paper says the Conservatives are drawing up proposed legislation which will make it much harder for public sector workers to call a strike.
The paper says the moves come as education secretary Michael Gove "threw down the gauntlet" to teaching unions over planned strikes.
Union leaders say a planned walkout by up to a million public sector workers on Thursday could be the biggest downing of tools since the General Strike of 1926, the paper reports.
A Conservative source tells the paper "Margaret Thatcher and Norman Tebbit pioneered the first wave of union reforms; now it is time to take the next step.
"It is wrong for workers in vital public services such as schools to walk out when the majority of members have not voted to do so.
"We hope to put an end to nearly all public sector strikes."
The paper notes that the Tories would have to win an outright majority in 2015 to implement the plans because of the opposition of their Lib Dem coalition partners.
And it quotes a Labour spokesman as saying "There is no justification for new laws to punish millions of trade unionists for exercising their right to protect schools and schoolchildren from unjustified cuts in standards and teachers' terms and conditions."
A poll in the Sun on Sunday suggests that just over half of people - 51% - think a strike should be called only if a majority of those eligible to vote for it are in favour.
However substantial majorities in the survey support the right of teachers and tube and train drivers to strike, although most oppose the right of police, firemen and nurses to stage walkouts.
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