Xi Jinping, the heir apparent to become China's next president, raised more than a few eyebrows during his current trip to five European countries with what was perceived to be an unusual diplomatic act. The vice-president handed two books to German Chancellor Dr Angela Merkel as a gift when they met for formal talks in Berlin on Monday. Along with the books - noticeably both written by former president Jiang Zemin - Xi passed the latter's 'greetings and good wishes' to Merkel, according to Xinhua. President Hu Jintao, the man Xi is scripted to succeed in less than five years' time, was conspicuously left out of the context. This suspicious break from diplomatic protocol immediately sparked wild speculation in some overseas media. If everything goes according to strictly practised custom, greetings and messages from Hu or Premier Wen Jiabao would be the first thing Xi conveys to his host. Merkel is not known to be Jiang's personal friend; when she began her first tenure in November 2005, Jiang had already left all official positions. It did not require too much imagination to interpret Xi's gift presentation as a hidden rift within the Communist Party leadership bursting to the surface. What happened, or perhaps rather what did not happen, at a high-level party plenum last month remains a question mark. Despite widespread reports that Xi would be made vice-chairman of the Central Military Commission to buttress his position as Hu's heir apparent, the vice-president did not get the nod. Under the well-scripted party succession procedure, the non-anointment was enough to get speculation going that despite the harmonious surface, party factional fighting is still very much alive. After all, Xi was known to be the dark horse who came from behind to beat Hu's top prot?g?, Li Keqiang, in a high-profile succession competition two years ago. Xi came from a completely different background than Hu, who cut his political teeth in the grass-roots Communist Youth League. The son of old revolutionary Xi Zhongxun and known as the new frontman for the 'gangs of princelings', Xi was understood to be closer to Jiang. Adding a twist to the speculation was that Jiang, who no longer holds any official position, has recently been as hyperactive as ever. The 83-year-old ex-president almost upstaged Hu at the all-important National Day parade to mark the 60th anniversary of the People's Republic. Jovial and chatty, Jiang appeared more than 20 times on China Central Television's live broadcast. His re-emergence into the limelight on October 1 proved to be no one-time act, as about 10 days later, he made national headlines with his calligraphy for a Chinese-character museum in Henan province . To top it all off, Xi has proved to be an outspoken character. Compared with the staid caution of Hu and other Standing Committee leaders, Xi has a track record of making maverick moves, especially on overseas tours. In February when visiting Mexico, the vice-president launched into a rant that characterised foreigners as 'having a full stomach and nothing better to do than try to point fingers at our country'. But some China watchers said Xi was unlikely to act in such an impromptu manner during important bilateral talks with a big Western country such as Germany. Ong Yew-kim, senior research fellow at Chinese University of Hong Kong, said it was unlikely Xi would take the opportunity to show off his closeness with Jiang to upset Hu. 'On the surface, it did seem odd for Xi to give the books authored by Jiang to Merkel, but it can't be his personal decision,' Ong said. 'At this diplomatic level, all exchanges would have to be approved by the Politburo Standing Committee.' What's more, the books - one on energy, the other on information technology - were actually the central leadership's choice, he said. 'Beijing wants to send a specific message to Merkel - that it's interested only in talking economic and technological co-operation with Germany,' Ong said. 'Only there lie the mutual interests and common ground; political differences should be transcended.' Merkel would perfectly understand the message as well, he added. It took quite an effort for the German leader to gain back Beijing's friendship after she received the Dalai Lama in Berlin two years ago.