What changes is Vladimir Putin proposing to Russia's constitution?

Russians are casting their ballots this week in a vote on constitutional reforms that could prolong President Vladimir Putin's hold on power.

Putin proposed the changes in January and they were quickly approved by Russia's two houses of parliament and regional lawmakers.

A nationwide vote to approve the reforms planned for April was postponed as Russia registered a surge of coronavirus infections.

Polling stations opened last week and close on Wednesday to minimise overcrowding. On the last day of the ballot, here is an overview of the proposed changes, the first reforms to the country's basic law since 1993.

The most discussed amendment would reset Putin's constitutional term-limit clock to zero. Putin first came to power as prime minister in 1999 under Boris Yeltsin before being elected President in 2000. He served the maximum two consecutive terms between 2000 and 2008 before a four-year stint as prime minister. He returned to the Kremlin in 2012 for a newly expanded six-year mandate and was re-elected in 2018.

Other constitutional changes expand the role of parliament, but they also strengthen the already-powerful role of the president.

The president will have the right to dissolve parliament if it refuses to support the candidacy of a minister proposed by the head of state three times in a row. They will also have a greater say over the work of the Constitutional and Supreme Courts and prosecutors.

The reform also strengthens the role of the State Council, currently an advisory body.

In line with Putin's conservative views, the reforms enshrine a mention of Russians' "faith in God" despite Russia's long history as a secular country. The reform also stipulates that marriage is a union between a man and a woman, effectively banning gay marriages.

The changes designate Russian as "the language of the people who form the state," and senior officials are barred from holding dual citizenship or residence permits in other countries.

The new amendments ban giving away Russian territory and outlaw calls promoting such a move. This amendment would ensure that Russia keeps Crimea, which it annexed from Ukraine in 2014, and the Kuril Islands -- disputed with Japan for decades.

The amendments also seek to protect the "historic truth" about the country's role in World War II and honour the memory of "the defenders of the fatherland".

The Russian leader has repeatedly railed against attempts to "rewrite" history and complained that the West does not fully appreciate the huge losses suffered by the Soviet Union during World War II.

The reforms also place the constitution above international law, giving priority to Russian legislation in the case of a contradiction with international statutes. The constitutional reforms guarantee a minimum wage that should not be below the subsistence level and state pensions regularly adjusted to inflation. The amendments spell out principles of "justice and solidarity between generations" to ensure the proper functioning of the pension system.

Environmental stipulations include "reducing the impact of economic activities" on nature and enshrine "a responsible attitude towards animals".