Varieties of criticism
Conservative criticism has nothing much to do with "left-wing" or "right-wing", because left-wing people are often very conservative, in the defined sense, while right-wing people can also be very radical, in the defined sense. The difference between "radical" and "conservative" has more to do with the belief in whether "a change to something genuinely new" is really possible and necessary. Radicals typically believe strongly that such change is highly desirable and necessary, and that it can be achieved. Their criticism is that there is "not enough" change. Conservative critics, by contrast, are very skeptical about any such change, because they feel the change is really "just another form" of something that already exists.
Left-wing nationalism
In Poland itself, the PPS is considered pro-independence and patriotic left-wing (in contrast with the internationalist left-wing) rather than left-wing nationalist. The term nationalism is used nearly exclusively for the right-wing national democracy of Roman Dmowski and other officially far-right movements such as National Radical Camp and National Revival of Poland. Nowadays, notable parties and organizations that come the closest to the idea of a left-wing nationalism are Self-Defence of the Republic of Poland under the leadership of Andrzej Lepper and Zmiana led by Mateusz Piskorski. Both advocate patriotism (at times even nationalism), social conservatism, Euroscepticism, anti-imperialism (strong criticism of a NATO and American foreign policies) and economic nationalism. The Self-Defence won 53 seats out of 460 in 2001 elections and 56 in 2005. From 2005 to 2007, it was in the coalition government with two other parties (one right-wing and the other nationalist). Since then, it has no representatives in the Polish Sejm.