Joe Biden rounds on Donald Trump as Ukraine controversy escalates

Joe Biden has accused Donald Trump of abusing his power, as the row over the former vice-president’s son’s business dealings in Ukraine escalated over the weekend.

Mr Biden sought to turn the tables on the US president and prevent the controversy over his son, Hunter, derailing his bid for the nomination.

His intervention came as the latest opinion poll in Iowa showed that he had fallen behind Massachusetts senator Elizabeth Warren in the race to be the party’s presidential candidate next year.

Even the slightest hint of impropriety could prove hugely damaging to Mr Biden, whose often halting performances on the campaign trail have seen his status as the Democratic front-runner eroded in recent weeks.

The controversy, which has intensified the long-running feud between Mr Trump and the former vice-president,centres on Hunter Biden’s involvement with Burisma, Ukraine’s natural gas producer, which was being investigated by Ukrainian prosecutor general Viktor Shokin.

Mr Trump and his supporters allege that as vice-president, Mr Biden put pressure on Ukraine to sack Mr Shokin to stymie the investigation, an accusation which was angrily denied.

Mr Shokin’s successor has since said there was no evidence of wrongdoing by Hunter Biden.

Speaking in Iowa, Mr Biden told reporters:  “I have never spoken to my son about his overseas business dealings.”

In turn, he accused Mr Trump of putting pressure on the new Ukrainian president Volodymyr Zelensky to re-open the investigation into Hunter Biden’s company for political purposes.

According to the Wall Street Journal, Mr Trump did so “about eight times”.

It is alleged the US president used a delayed package of military aid to put pressure on Mr Zelensky in what has been seen as an attempt to persuade a foreign government to effectively intervene in the 2020 US presidential election.

This alarmed an intelligence service whistleblower, who raised the issue.

However, the White House has resisted attempts by the Democrat-controlled House Intelligence Committee to see details of the whistleblower's complaint.

“Here’s what I know. Trump should be investigated,” Mr Biden said in Iowa.

“He’s doing this because he knows I’ll beat him like a drum. And he’s using an abuse of power and every element of the presidency to try to smear me ... Ask the right questions.

“This appears to be an overwhelming abuse of power. We have never seen anything like this from any president.”

Mr Trump remained defiant, insisting  his conversation with Mr Zelensky was “perfectly fine and routine.”

He wrote on Twitter: “Now that the Democrats and the Fake News Media have gone ‘bust’ on every other of their Witch Hunt schemes, they are trying to start one just as ridiculous as the others, call it the Ukraine Witch Hunt.”