Countries may ditch a detailed checklist for what their pledges under a new climate agreements should contain, given deep splits over their breadth and scope, and whether they should draw a clear line between rich and poor nations.

A two-week Lima conference entered its critical phase on Tuesday, as ministers from dozens of countries joined their national negotiators.

All countries have committed to sign a new climate agreement in Paris at the end of 2015, pledging climate action beyond 2020.

They have also agreed to publish pledges under the agreement by June next year at the latest.

The main aim of the Lima conference this week is to agree the precise format for these pledges, called Intended Nationally Determined Contributions (INDCs) in UN jargon. But that has set up a showdown over who should offer the most.

U.N. Secretary-General Ban Ki-moon implored countries to try harder, in prepared remarks to the conference in Lima on Tuesday, but skirted the issue of how to resolve deep differences on the format for the pledges.

“I am deeply concerned that our collective action does not match our common responsibilities,” Ban told ministers.

“We must reach a common understanding on the scope and status of Intended Nationally Determined Contributions or INDCs.”

One possible compromise may simply be to delete a detailed list of what information countries should provide in their pledges - a list currently contained in an annex to a draft Lima decision, said analysts and environmental groups following the process.

LESS ACCOUNTABLE?

Without a detailed template, the pledges would be less accountable, with less scope for countries, the United Nations and outside observers to compare, analyze, aggregate and challenge them.

The European Union has insisted that the pledges should only focus on carbon cuts.

A long-running sore in the U.N. talks has been a desire among richer countries to focus on new emissions targets, which throws the onus on developing countries whose emissions are growing fastest as they try to improve their living standards.

By contrast, developing countries also want to focus on pledges of aid, for example to help them cut emissions and prepare for more extreme weather.

Britain’s minister for energy and climate change, Ed Davey, said that focusing on ambitious targets to cut carbon emissions would complement climate finance, by cutting the costs of low-carbon technologies.

“The two go together,” he told reporters on Tuesday.

Asked whether the conference may end up ditching a detailed format for the pledges, Davey said: “Clearly we do need to make progress (and see) that the INDC concept … goes forward. I am confident we can get agreement.”