<p>Billionaire U.S. presidential candidate Michael Bloomberg on Tuesday said his campaign had unknowingly used prison workers to make telephone calls on his behalf.</p>.<p>Bloomberg, who last month entered the Democratic Party race to face Republican President Donald Trump in the November 2020 election, said the campaign had ended its relationship with a company that used prison labor for making phone calls.</p>.<p>"We do not support this practice and we are making sure our vendors more properly vet their subcontractors moving forward," Bloomberg said in a statement.</p>.<p>Bloomberg said the campaign learned of the ties to prison labor when a reporter called. The Intercept, a news website, was first to report the use of prison labor.</p>.<p>Ranked by Forbes as the eighth-richest American, Bloomberg has spent more on campaign ads in the last few weeks than his main Democratic rivals have all year.</p>.<p>He has so far failed to crack into the top tier of candidates in public opinion polls.</p>.<p>A Reuters/Ipsos opinion poll conducted on Dec. 18-19 showed about 5% of Democratic-leaning voters support the billionaire former mayor of New York. Recent polls show former Vice President Joe Biden, Senator Bernie Sanders and Senator Elizabeth Warren are the party's leading candidates. </p>
<p>Billionaire U.S. presidential candidate Michael Bloomberg on Tuesday said his campaign had unknowingly used prison workers to make telephone calls on his behalf.</p>.<p>Bloomberg, who last month entered the Democratic Party race to face Republican President Donald Trump in the November 2020 election, said the campaign had ended its relationship with a company that used prison labor for making phone calls.</p>.<p>"We do not support this practice and we are making sure our vendors more properly vet their subcontractors moving forward," Bloomberg said in a statement.</p>.<p>Bloomberg said the campaign learned of the ties to prison labor when a reporter called. The Intercept, a news website, was first to report the use of prison labor.</p>.<p>Ranked by Forbes as the eighth-richest American, Bloomberg has spent more on campaign ads in the last few weeks than his main Democratic rivals have all year.</p>.<p>He has so far failed to crack into the top tier of candidates in public opinion polls.</p>.<p>A Reuters/Ipsos opinion poll conducted on Dec. 18-19 showed about 5% of Democratic-leaning voters support the billionaire former mayor of New York. Recent polls show former Vice President Joe Biden, Senator Bernie Sanders and Senator Elizabeth Warren are the party's leading candidates. </p>