BERLIN (Reuters) - Chancellor Angela Merkel's conservatives are losing support ahead of elections in three German states on Sunday that are shaping up as a litmus test of her migrant policies.
A survey by pollster INSA showed Merkel's Christian Democrats (CDU) had lost support over the last week in two of the three states, with their closest rival catching up on the party in the third.
Facing the biggest test of her decade in office, Merkel is scrambling to secure a Europe-wide plan to address the refugee crisis but many voters are losing faith in her ability to make it work, and want Germany to close its borders instead.
The three states voting on March 13 have a combined population of about 17 million, about a fifth of Germany's 81 million.
The INSA poll showed support for the CDU falling to 28.5 percent in the wealthy southwestern state of Baden-Wuerttemberg, down from 30 percent in a comparable poll in late February. The ruling Greens extended their lead, with 33.5 percent support.
In Rhineland-Palatinate, also in western Germany, the poll showed the CDU and the Social Democrats (SPD), who rule in coalition at the federal level, tied at 35 percent. The CDU had previously held a narrow lead.
A poor showing by the CDU in the state elections would increase pressure on Merkel to reverse course on her migrant policy, 1-1/2 years before the next federal election, when she is likely to seek a fourth term.
In Saxony-Anhalt, in the east, the INSA poll showed the CDU losing half a percentage point to 29 percent, with the anti-immigration Alternative for Germany (AfD) party gaining 2 points to 19 percent.
In a March 6 municipality vote in the western state of Hesse, home to Frankfurt, the CDU pipped the SPD with 28.2 against 28.0 percent. The AfD was the third strongest party, with 13.2 percent of the vote, preliminary results showed.
(Reporting by Paul Carrel; Editing by Janet Lawrence)