A number of Wednesday's papers lead with a warning from the security service MI5. The Financial Times reports on director-general Ken McCallum's warning that Russian spies are on a "sustained mission to generate mayhem" in Britain. It says the number of cases of spying by other states against the UK has "shot up" by nearly 50%.The I also leads with the warning from the security service, reporting MI5's concerns that escalating conflict in the Middle East could lead to an Iranian attack on British soil. The Daily Mail calls Ken McCallum's annual update "chilling". The lead story also reports that the UK is facing a "staggering terror threat from radicalised teens" because of minors consuming, and being "poisoned" by, extremism online. The Daily Express also leading with the security warning and reports that MI5 has "one hell of a job on its hands" to manage the threats faced by the UK.The Times splashes with a story that net migration has "entirely" fuelled a "record rise" in the UK's population, which has risen at the fastest rate in the last 53 years. It reports that the population surged to 68.2 million in the middle of last year despite the number of deaths outnumbering births in Britain. It says the data, from the Office for National Statistics, will reignite pressure on the government to manage immigration. The Guardian has an exclusive splash that says that the chancellor is "pushing ahead" with her borrowing for investment plans despite concerns over rising government debt. Rachel Reeves is waiting for an imminent decision from the Office for Budget Responsibility that would allow the government to increase investment in major projects, according to the paper. A picture of Rosie Duffield is on the cover of Wednesday's Daily Telegraph to point readers to an interview with the former Labour MP inside. Duffield, who quit the party in September, has told the broadsheet that the prime minister is surrounded by an "abusive boys club". The paper's top story says the government is looking at making cuts to the tax-free lump sum savers can withdraw from their pensions. It says the government has asked one of the country's leading pension providers to assess the impact of cutting it from a maximum of £268,275 to £100,000. The Daily Mirror leads with a story about Madeleine McCann "suspect" Christian Brueckner. It reports that prosecutors are scrambling to charge Brueckner, who in the coming months will be freed from jail where he was serving a seven-year sentence for raping a 72-year-old American tourist in Praia da Luz in 2005. He had been on trial since February charged with three counts of rape and two counts of sexual abuse, but has now been cleared."Wagatha Thrifty" leads the Metro with the story that barristers for Coleen Rooney and Rebekah Vardy have been back in court in a dispute over Mrs Rooney's legal costs during the so-called Wagatha Christie libel trial. Mrs Vardy was ordered to pay 90% of Mrs Rooney's legal fees, which were originally estimated at £540k, but have since risen to £1.8m. The paper focusses on the price of a bottle of water at a hotel minibar after it was revealed that Mrs Rooney's legal fees included the cost of one of her lawyers staying at the five-star Nobu Hotel in London. "Look what Taylor made us do" is leading The Sun, which says that Sadiq Khan and Yvette Cooper pressed police to give Taylor Swift a "royalty-style" police escort to Wembley when her Eras Tour came to London this summer. It says an "elite Met protection unit" turned down the original request for an escort and only agreed after the London mayor and home secretary intervened. "Downing Street was like a crack den": Boris Johnson's words are the splash for the Daily Star. It reports that when Johnson took office, he was not happy with the state of the private dwelling above 11 Downing Street reserved for serving prime ministers. It was previously reported he had taken a handout of at least £112,000 from Lord Brownlow to fund home improvements, which he told LBC was because it looked like a "crack den".