AfD was formed in 2013 and was initially profiling itself as a party for Eurosceptics, but the party has since split into two factions, with one more vocal on right-wing politics.
Ms Petry, a mother-of-four, has been a Speaker for the party since its birth, but was elected ‘principal Speaker’ – de facto party leader – in June last year.
Her opponent, Bernd Lucke, said Ms Petry and the election of her as leader, was turning AfD into ‘a Pegida party’.
A member of AfD’s right-wing faction, Ms Petry has pushed an anti-immigrant agenda, and has been vocal in her critique of Merkel’s migration policies.
On Saturday, Ms Petry told the Mannheimer Morgen daily that a border police officer ‘must stop illegal border crossings, and also make use of his firearm if necessary.’
She added that: ‘no policeman wants to fire on a refugee and I don’t want that either. But the last resort includes the use of armed force.’
Germany saw nearly 1.1 million asylum-seekers enter the country last year and the AfD has been gaining in support as more people question whether the government will be able to deal with the influx.
As Chancellor Angela Merkel has been criticised for her refusal to reverse her ‘open doors’ migration policy, Ms Petry’s AfD has grown.
A poll last week found that more than 11 per cent of the German population would vote AfD, as support for Merkel’s coalition government dropped down to 37 per cent.
Her interview was widely condemned both by politicians and the force itself, with the national police union slamming her suggestion, saying no German police officer would shoot at a refugee.
‘Whoever proposes such a radical approach apparently wants to overturn the rule of law and exploit the police,’ Joerg Radek, vice-chairman of the GdP police union, said in a statement.
Angela Merkel’s second in command,Vice Chancellor Sigmar Gabriel, called for AfD to be put under observation by the government agency that tracks extremists.
Vice Chancellor Gabriel told Bild newspaper that ‘there is massive doubt that (the Alternative for Germany party) stand by the free democratic order of the republic.’
Chancellor Angela Merkel, meanwhile, received support from an unlikely source for her handling of Germany’s refugee crisis.
Baden-Wuerttemberg governor Winfried Kretschmann, a member of the Greens party that is in opposition at the federal level, told Berlin’s Tagesspiegel newspaper the chancellor’s insistence on ‘working step by step’ on a European solution to the refugee crisis was the correct path.
‘Which of her counterparts in the EU will hold Europe together if she fails?’ he asked. ‘Far and wide there’s nobody in sight. Therefore I pray every day that the chancellor remains healthy.’
Meanwhile, neighbouring Austria has announced that it will step up deportations of migrants and is adding Morocco, Algeria and other states to a list of countries it deems safe, enabling it to send people back there more quickly/
Despite an initial outpouring of sympathy for the migrants, public concern about the influx have fuelled a rise in support for the far right in Austria, and opposition to the coalition government of Social Democrats and conservatives has grown.
In an apparent move to address those concerns, the government announced this month that it would cap the number of asylum claims at 127,500, or 1.5 percent of the country’s population, over the next four years.
Now the government has decided to carry out at least 50,000 deportations in the same period, according to a summary of an agreement between the interior, defence and integration ministries published on Sunday.
It will also offer up to 500 euros (£380) to migrants whose asylum applications have been turned down if they agree to be deported, the summary said.
Europe has endured a huge influx of migrants, most of whom undertake a dangerous journey in search of a better life. On Saturday, at least 37 people drowned, including children and babies, when their boat capsized during the short trip from Turkey to Greece.