In his new book, Donald Trump’s vice-president, Mike Pence, protests his loyalty to his former boss but also levels criticisms that will acquire new potency as Trump prepares to announce another presidential run and the Republican party debates whether to stay loyal after disappointment in last week’s midterm elections.

According to Pence, Trump mishandled his response to a march staged by neo-Nazis in Charlottesville in August 2017, a costly error that Pence says could have been avoided had Pence called Trump before a fateful press conference in which Trump failed to condemn “the racists and antisemites in Charlottesville by name”.

Also in Pence’s judgment, “there was no reason for Trump not to call out Russia’s bad behaviour” early in his term while beset by investigations of Russian election interference on Trump’s behalf and links between Trump and Moscow.

“Acknowledging Russian meddling,” Pence writes, would not have “somehow cheapen[ed] our victory” over Hillary Clinton in 2016.

Pence does not stop there. Among other judgments which may anger his former boss, he says Trump’s claimed “perfect call” to Volodymyr Zelenskiy of Ukraine in 2019, the subject of Trump’s first impeachment after he withheld military aid in search of political dirt, was in fact “less than perfect” – if not, in Pence’s judgment, impeachable.

Pence also says that in January 2021 he urged Trump to make a farewell address to the nation and to encourage unity after the deadly Capitol attack he says Trump incited, the subject of Trump’s second impeachment. Trump remains unrepentant.

Pence, famously devout, writes that he prayed for Trump throughout his presidency, and after urging a farewell address as given by “every president since George Washington … urged him one more time to take time to pray”.

Perhaps unsurprisingly, the thrice-married, genital-grabbing, greed-worshipping Trump does not appear to have taken the advice to pray or be prayed for. A few days after the conversation about a farewell address, Pence writes, he “reminded” Trump “that I was praying for him”.

“Don’t bother,” Trump said.

Trump’s reluctance to be told what to do, to be told he is wrong or to credit advisers for anything mean Pence’s book would risk provoking attacks as Trump prepares to announce his next presidential campaign even if Pence were not a potential rival.

Pence’s memoir, So Help Me God, will be published in the US on Tuesday. It has been trailed in the US media, including in a column published by the Wall Street Journal which presented the former vice-president’s version of events before, on and after January 6, when supporters incited by Trump attacked Congress in an attempt to stop certification of Joe Biden’s election win.

Pence did not do as Trump demanded and reject electoral college results from key states while performing his ceremonial role in Congress. The House January 6 committee has presented Pence as something of a hero, but his reward on the day itself was a rampaging mob, members of which called for him to be hanged as a gallows was erected outside.

In excerpts of an interview due to be broadcast on Monday, Pence told ABC News: “The president’s words [on 6 January 2021] were reckless and his actions were reckless. The president’s words that day at the rally endangered me and my family and everyone at the Capitol building.”

Until last week, Pence’s book seemed likely to read as something of a balancing act, between loyalty to the president to whom in his own words he “always deferred” – and to that president’s supporters – and the service of ambition which has seen Pence visit early voting states and address conservative groups.

Pence writes that after Biden’s victory, he advised Trump to follow a path to the 2024 nomination, treating his defeat as not “a loss – just an intermission”.

“Thirteen days after the 2020 election,” Pence writes, “I had lunch with President Trump. I told him that if his legal challenges came up short, he could simply accept the results, move forward with the transition and start a political comeback, winning the Senate runoffs in Georgia, the 2021 Virginia governor’s race, and the House and Senate in 2022. Then he could run for president in 2024 and win. He seemed unmoved, even weary: ‘I don’t know, 2024 is so far off.’”

Republicans lost the Senate runoffs in Georgia, won the Virginia governor’s race in large part by distancing their candidate from Trump, then missed their midterms target. Last Tuesday, an expected “red wave” failed to show.

Instead, Democrats are celebrating while Republicans find themselves contemplating a narrow and unruly majority in the US House, the far right ascendant, and at least two more years in the Senate minority thanks to Democratic victories in Arizona, Nevada and Pennsylvania, the only seat flipped so far.

A Republican backlash against Trump has formed quickly, particularly over his endorsements of election-denying candidates who lost Senate races and contests for governor and other state posts.

To make matters worse for Trump, the Republican governor of Florida, Ron DeSantis, enjoyed a landslide re-election, a rare bright spot for the GOP, and has shot to the fore in polls of the nominal field for 2024.

Regardless, aides to Trump have indicated that he will plough ahead and announce his 2024 campaign – his third consecutive run – at his Mar-a-Lago resort in DeSantis’s state on Tuesday.

Trump has repeatedly attacked DeSantis. But regarding the governor, at least, Pence keeps his own powder dry. In his book, the former vice-president and Trump coronavirus taskforce chief mentions his potential primary rival just once, praising him for his handling of the pandemic.

Pence doggedly claims the Trump administration passed its Covid test with flying colours, even praising government scientists including Anthony Fauci – “a great source of comfort to millions of Americans” – who are now likely targets for investigation by House Republicans.

Under DeSantis, more than 82,000 people have died of Covid-19 in Florida, the third-highest state total. The national death toll is close to 1.1m.