Germany's governing parties have set out tougher measures against potential Islamist terrorists in the wake of December's Christmas market truck attack in Berlin.

Interior Minister Thomas de Maiziere, of the Christian Democratic Union (CDU), met Justice Minister Heiko Maas, of the Social Democratic Party (SPD), on Tuesday to agree the plans, and the pair presented them at a press conference in the afternoon.

"Maas and I have agreed a series of measures," de Maiziere said, before listing the bullet points: tougher place-of-residence obligations for those who have faked their identity, rules that make deportation easier, and tougher surveillance on individuals considered a potential danger. The minister also said there would be wider negotiations with countries of origin over people Germany wants to deport - in other words, including development aid.

"We agree that in the negotiations with countries of origin, all spheres of politics be included in those negotiations," de Maiziere said.

"What is important is that we have regulated the potentially dangerous individuals, and created new grounds for incarceration," said Maas. "But we're not starting from zero in any area - [we've] already discussed these measures."

Ankle tags and video cameras

The conservative minister had applied a little advance pressure before the meeting by expressing the hope that his center-left colleague wouldn't shrink from "really hard measures." "If we both speak seriously with one another, there are usually good results," he said.

Ankle tags will be used to track potential violent criminals

In fact, many of the measures that were agreed had been proposed by the justice minister the day before: not least creating the laws by which rejected asylum seekers could be imprisoned for up to 18 months while they awaited deportation.

At the moment, incarceration of asylum seekers is only allowed if deportation is likely within three months - a circumstance that allowed Anis Amri, the Tunisian who carried out the Berlin attack, to remain free, as the Tunisian government had not delivered the necessary papers.

Similarly, Maas had already declared his support for using electronic ankle tags as a preventative measure ahead of the meeting. This move would force those considered by intelligence agencies as potentially violent - or "Gefährder" ("Endangerers") in the spooks' jargon - to wear a tag that could be traced by GPS. At the moment, only felons convicted of serious crimes wear them on parole after a minimum of three years in jail.

In the aftermath of the Berlin attack, de Maiziere admitted there were 550 Islamist Gefährder (including Amri) in Germany, around half of whom had no German passport, and 62 of whom had had their asylum applications rejected.

The minister's proposals were welcomed by other ministers, though not without reservations. Eva Kühne-Hörmann, CDU justice minister in the central German state of Hesse, described the proposals as "bogus labeling" that "won't even work as a calming pill." "The problem is that crimes related to preparation in the area of terrorism only bring relatively mild consequences," she told "Der Spiegel."

But as Maas said before the meeting, ankle tagging "is no cure-all, but it will make the work of the security forces easier, and that's what we need now." Maas had also called for development aid to be stopped for countries that refuse to take deportees - though both the Foreign Ministry and the Development Ministry summarily opposed the idea as simplistic.

Anis Amri was a rejected Tunisian asylum seeker

Nevertheless, Maas was adamant that more pressure could be applied: "We think that those don't cooperate, who don't want to take back their citizens, can be pressured to comply in a variety of ways," he said.

Opposition doubts

Opposition parties, meanwhile, were quick to express their skepticism. The Green party chairwoman Simone Peter called the government's plans "symbol politics that would not make much difference. We can see that in the Amri case - neither an ankle tag or video surveillance would have stopped him."

Nevertheless, other major Green party figures were more amenable to the new measures. Winfried Kretschmann, Green party state premier in Baden-Württemberg, told the "Stuttgarter Zeitung" on Tuesday that he was open to both extended incarceration for deportees and ankle tagging. "We will go to the limits of what is constitutionally possible with the Gefährder, if that is what is necessary," he said.

Meanwhile Bernd Riexinger, Peter's counterpart in the socialist Left party, even called for de Maiziere's resignation, accusing the interior minister of using the tougher laws to distract the country from his own failure. "It's time that de Maiziere finally took responsibility for the failures of the authorities, which are completely obvious," he said in a press conference on Monday. "There are laws for all the attacks carried out in the past year, there are laws that are completely sufficient. The question is, why weren't these laws implemented? Why wasn't Amri taken into custody ahead of time? These are the questions we should be asking."