Two leading consultants have urged BP shareholders to vote against chief executive Bob Dudley's $12.7 million 2014 pay, saying it was not in line with the energy major's poor performance.

Glass Lewis and Pensions & Investment Research Consultants (PIRC), which advise institutional shareholders and issue proxy vote recommendations, both said Mr Dudley's remuneration exceeded that of its European peers.

Investors have become increasingly vocal over executive remuneration in recent years. Lawmakers have adopted new rules on pay transparency and given shareholders more power to block payouts.

"The changes in CEO pay over the last five years are not considered in line with the company's financial performance over the same period," PIRC said.

Mr Dudley's 2014 remuneration, which rose by more than 20 per cent from 2013, despite a slide in BP's profits due to falling oil prices, will be put to vote at its annual general meeting on April 16.

Glass Lewis said BP pays "more to its CEO than the median CEO remuneration for a group of European Energy companies. Overall, the company performed worse than the peers".

BP executives received bonus payouts of 73 per cent of the company's maximum limit, despite below-target performance on several metrics, according to Glass Lewis.

In one instance, Glass Lewis "strongly" questioned BP's policy of granting bonuses of up to 150 per cent of salary based on the absence of major safety and environmental incidents.

Mr Dudley's 2014 salary and annual bonus fell to $2.95 million from $4.21 million in 2013 but deferred bonuses and performance shares' awards rose to $9.79 million from $5.96 million a year earlier, according to a BP regulatory filing.

As a result, his total remuneration rose to $12.74 million in 2014, from $10.17 million in 2013.

BP rejected the claims.

"Executive pay is closely linked to BP's performance and is defined by the remuneration policy which was overwhelmingly approved by our shareholders at last year's AGM," a spokesman said.

"Remuneration for 2014 was entirely in line with this policy and reflected the delivery of BP's strategic targets over the past three years."

Glass Lewis also recommended voting against Dudley's 2013 remuneration last year, but the vote won by more than two thirds of shareholder support.

Another proxy advisor, Institutional Shareholder Services, recommended a vote in favour of the 2014 remuneration, saying BP had addressed disclosure issues.