Nigeria's main opposition party has called on its MPs to block all legislation including the 2014 budget.

This would remain the case until "the rule of law" was restored in oil-rich Rivers state and "Nigeria in general", the All Progressive Congress said.

The Rivers state governor fell out with President Goodluck Jonathan last year and defected to the APC.

Mr Jonathan's party has lost its majority in the lower chamber of parliament following other defections.

Analysts say the row centres around Mr Jonathan's undeclared intention to contest elections in 2015 for the governing People's Democratic Party (PDP).

Nigeria is one of the world's biggest oil producers, with Rivers state supplying about 40% of all the country's oil, according to business information firm Ngex.

'De facto military governor'

The row between Rivers state Governor Rotimi Amaechi and President Jonathan's supporters has paralysed politics in the state, with the police stopping the local state assembly from meeting in its building.

The APC accuses the state police chief of taking sides and exacerbating tensions - it wants his removal, as demanded by Nigeria's federal House of Representatives last year.

"The culture of lawlessness and impunity" in Rivers was being promoted by the presidency and the state's police chief Joseph Mbu, the APC national executive committee said in a statement.

It went onto describe Mr Mbu as "the de facto military governor of Rivers State and sole administrator of the PDP in the state".

Mr Mbu has denied taking sides in the political dispute.

The APC's call to block legislation will also affect the confirmation of ministers and the security chiefs recently appointed by the president.

MPs returned from recess last week and were due to start considering the budget, which has never been blocked before.

BBC Nigeria analyst Aliyu Tanko says if it is not passed within the next couple of months, it will start to affect government business as there will be no money for salaries and other projects.

The PDP said the APC's directive was "as a clear and direct call for anarchy".

It is the latest crisis to hit Mr Jonathan, whose leadership has recently come in for high-profile criticism from within the PDP, including from former President Olusegun Obasanjo, who called on him not to seek another term in office.

Mr Jonathan moved from the vice-presidency to the presidency in 2010 after his predecessor, Umaru Yar'Adua, died in office.

He won presidential elections the following year.

The PDP has won every national election since the end of military rule in 1999.