Speaking to a rally of members of the ruling Conservative Party at their annual conference in Birmingham, central England, Johnson invoked the opening line of the French national anthem: "Allons enfants de la patrie," which translates as "Let us go, children of the fatherland" in English.
"We say to the people, not since 1789 has there been such tyranny in France," Johnson joked, referring to the year of the French revolution. "I am very keen to welcome talented French people to London." He noted that there are already 240,000 French nationals in the capital.
In June, Prime Minister David Cameron triggered a war of words with France by vowing to "roll out the red carpet" for French companies if Hollande followed through on his election pledge to tax the wealthy. In its 2013 budget last month, Hollande's government announced 20 billion euros ($26 billion) of tax increases, including a 75 percent levy on incomes over 1 million euros, and the elimination of limits on the wealth tax.
A decision by France's richest man, Bernard Arnault, CEO for LVMH Moet Hennessy Louis Vuitton, to seek Belgian citizenship created a media frenzy over tax exiles, prompting the newspaper Liberation to run a front-page headline that read: "Get lost, rich bastard." Hollande said Sept. 9 it's patriotic to pay taxes.
Johnson arrived in Birmingham amid continued speculation about whether he intends to challenge Cameron for the Conservative leadership if the premier fails to secure a majority at the next general election due in 2015.
Buoyed by re-election in May and the success of the London Olympics in August, Johnson has increasingly been touted by Tory activists as a possible successor to Cameron, whose poll ratings have fallen.
The mayor, who has criticized government policy in areas such as welfare, has repeatedly failed to rule himself out as a future Tory leader. In a bid to quell doubts over his loyalty to the premier, Johnson paid tribute to Cameron on Monday.
"No one should have any cause to doubt my admiration for David Cameron," Johnson said. "In tough circumstances, he and George Osborne and the rest of the government are doing exactly what's needed for this country to clear up the mess that Labour left" when it was ousted from power in 2010, leaving a record budget deficit.
In an LBC radio interview earlier Monday, Johnson compared talk that he may challenge Cameron's leadership to a storyline in the television costume drama "Downton Abbey," saying that "in Tory party politics, there has always got to be some kind of plot."
A survey of Tory members for the ConservativeHome website found that Johnson had a net satisfaction rating of plus 91, higher than any Cabinet minister. Cameron's was only just positive, at plus one. The website questioned 1,872 people on Oct. 4 and 5.
Asked at Monday's rally about his formula for ensuring the Conservatives beat Labour in the next election in 2015, Johnson said the Tories have to "locate ourselves squarely in the centre ground of British politics." He said he has no "magic prescriptions for winning elections except keep bashing the Labour Party," which he described as "barely reformed Marxists."
Johnson "is clearly trying to establish himself as the man the Tories have to turn to when the present leadership is seen to have failed," his biographer, Andrew Gimson, said in a telephone interview.
Ken Clarke, a minister who challenged Cameron for the leadership of the party in 2005, said today that Johnson needs to "settle down" if he wants to be taken seriously in future.
"If he really wants to be prime minister, for serious reasons, not just because he'd get his picture in the paper more often, he really does have to settle down and demonstrate he can seriously deliver on some complicated subject," Clarke told delegates at a fringe meeting in Birmingham.
-- With assistance from Robert Hutton in Birmingham, England.
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