At what has been dubbed a "make or break" meeting of the World Trade Organization (WTO) in Bali this week, Indonesia's Trade Minister told CNBC there was a less than 50 percent chance of a global trade deal.
The long-anticipated deal has been in discussion since the group was first formed in 1995, and has been touted as having the potential of adding $1 trillion to the global economy by opening up international trade relations. However, political battles between member nations have hindered progress, though hopes were high that this week's meeting could lead to a breakthrough.
(Read more: 'Make or break' trade deal: What you need to know)
Asked what the chances were of closing a deal at the summit, Indonesia's Trade Minister Gita Wirjawan told CNBC: "We are cautiously optimistic...It's probably in the high 40s [in terms of percentage points] and depending on how things go today, tomorrow and the day after, hopefully that number will creep up."
A key sticking point to pushing the deal through has been disputes over agricultural subsidy rules.
India is said to hold the key to success in Bali. Policy makers there have been unhappy with the idea of the WTO imposing restrictions on its policy of subsidizing food for the poor.
CNBC reported on Wednesday, however, that India's Commerce Minister Anand Sharma's showed no signs of budging on the issue in his opening comments at the meeting.
(Read more: India tops China as most attractive investment destination)
Wirjawan said he had previously been more optimistic on progress at Bali, but said members had recently faced a stumbling block which has decreased the chances of pushing a deal through.
"Until a few days ago we were optimistic, then something happened," said Wirjawan, declining to elaborate on the details.
"I don't think it's a question of lack of effort or time, but I think it's politically driven," he added, referring to the incident which was obstructing the deal.
Wirjawan told CNBC members had made progress in a number of other areas, however, particularly in regards to the least developed countries (LDCs) and on trade facilitation, but disputes over agriculture subsidy rules remained a sticking point.
"This [the lack of resolution on agriculture] relates to a politically centric issue that will require the kind of political will that has been talked about for a long time. In the absence of that we all understand that it's not going to be very good," he added.
(Read more: Trade talks in Bali will succeed: Former WTO chief)
The meeting follows tense negotiations in Geneva last week, when WTO representatives were unable to agree on the text for the deal to be decided in Bali.
A successful WTO deal could pave the way for further negotiations on what is known as the Doha Development Round a series of negotiations which aim to help poorer countries by lowering trade barriers.
The meeting started Tuesday and will finish on Friday.
— By CNBC's Katie Holliday: Follow her on Twitter @hollidaykatie