WARSAW, Poland (AP) — Poland's conservative ruling party faced its first test of support since it took power in November as by-elections to the Senate were held Sunday in the country's northeast.

The vote was held in the Lomza and Augustow region because its senator vacated his seat when he was recently appointed provincial governor. Among the six candidates is Anna Maria Anders who represents the ruling Law and Justice party.

The daughter of Poland's World War II commander, Gen. Wladyslaw Anders, she is an adviser on international affairs, in the rank of minister, to Prime Minister Beata Szydlo. At a recent observance in memory of her father, Anders was unexpectedly faced with demands from local people for bigger pensions.

Ruling party leader Jaroslaw Kaczynski has said the by-election is a test of support for the party that is introducing sweeping changes to state offices and to social benefits. The party won the presidency and a majority in parliament on promises of improving the living conditions of those who were left behind during Poland's economic development. So far it has decided on payment of bonuses to families with children and introduced a new tax on banks, to help pay for the benefits.

However, recent appointments to the Constitutional Court and to top positions in state media have led to massive street protests and censure from European Union leaders.